diff --git a/.credo.exs b/.credo.exs
index a9c6d0c..6bb5d59 100644
--- a/.credo.exs
+++ b/.credo.exs
@@ -22,16 +22,14 @@
         # In the latter case `**/*.{ex,exs}` will be used.
         #
         included: [
+          "{.credo,.dialyzer_ignore,.formatter,mix}.exs",
+          "config/",
+          "bench/",
           "lib/",
-          "src/",
-          "test/",
-          "web/",
-          "apps/*/lib/",
-          "apps/*/src/",
-          "apps/*/test/",
-          "apps/*/web/"
+          "profile/",
+          "test/"
         ],
-        excluded: [~r"/_build/", ~r"/deps/", ~r"/node_modules/"]
+        excluded: [~r"/_build/", ~r"/deps/"]
       },
       #
       # Load and configure plugins here:
@@ -64,126 +62,151 @@
       #
       #     {Credo.Check.Design.DuplicatedCode, false}
       #
-      checks: [
-        #
-        ## Consistency Checks
-        #
-        {Credo.Check.Consistency.ExceptionNames, []},
-        {Credo.Check.Consistency.LineEndings, []},
-        {Credo.Check.Consistency.ParameterPatternMatching, []},
-        {Credo.Check.Consistency.SpaceAroundOperators, []},
-        {Credo.Check.Consistency.SpaceInParentheses, []},
-        {Credo.Check.Consistency.TabsOrSpaces, []},
+      checks: %{
+        enabled: [
+          #
+          ## Consistency Checks
+          #
+          {Credo.Check.Consistency.ExceptionNames, []},
+          {Credo.Check.Consistency.LineEndings, []},
+          {Credo.Check.Consistency.MultiAliasImportRequireUse, []},
+          {Credo.Check.Consistency.ParameterPatternMatching, []},
+          {Credo.Check.Consistency.SpaceAroundOperators, []},
+          {Credo.Check.Consistency.SpaceInParentheses, []},
+          {Credo.Check.Consistency.TabsOrSpaces, []},
 
-        #
-        ## Design Checks
-        #
-        # You can customize the priority of any check
-        # Priority values are: `low, normal, high, higher`
-        #
-        {Credo.Check.Design.AliasUsage,
-         [priority: :low, if_nested_deeper_than: 2, if_called_more_often_than: 0]},
-        # You can also customize the exit_status of each check.
-        # If you don't want TODO comments to cause `mix credo` to fail, just
-        # set this value to 0 (zero).
-        #
-        {Credo.Check.Design.TagTODO, [exit_status: 2]},
-        {Credo.Check.Design.TagFIXME, []},
+          #
+          ## Design Checks
+          #
+          # You can customize the priority of any check
+          # Priority values are: `low, normal, high, higher`
+          #
+          {Credo.Check.Design.AliasUsage,
+           [priority: :low, if_nested_deeper_than: 2, if_called_more_often_than: 0]},
+          {Credo.Check.Design.DuplicatedCode, []},
+          {Credo.Check.Design.SkipTestWithoutComment, []},
+          {Credo.Check.Design.TagFIXME, []},
+          # You can also customize the exit_status of each check.
+          # If you don't want TODO comments to cause `mix credo` to fail, just
+          # set this value to 0 (zero).
+          #
+          {Credo.Check.Design.TagTODO, [exit_status: 2]},
 
-        #
-        ## Readability Checks
-        #
-        {Credo.Check.Readability.AliasOrder, []},
-        {Credo.Check.Readability.FunctionNames, []},
-        {Credo.Check.Readability.LargeNumbers, []},
-        {Credo.Check.Readability.MaxLineLength, [priority: :low, max_length: 120]},
-        {Credo.Check.Readability.ModuleAttributeNames, []},
-        {Credo.Check.Readability.ModuleDoc, []},
-        {Credo.Check.Readability.ModuleNames, []},
-        {Credo.Check.Readability.ParenthesesInCondition, []},
-        {Credo.Check.Readability.ParenthesesOnZeroArityDefs, []},
-        {Credo.Check.Readability.PredicateFunctionNames, []},
-        {Credo.Check.Readability.PreferImplicitTry, []},
-        {Credo.Check.Readability.RedundantBlankLines, []},
-        {Credo.Check.Readability.Semicolons, []},
-        {Credo.Check.Readability.SpaceAfterCommas, []},
-        {Credo.Check.Readability.StringSigils, false},
-        {Credo.Check.Readability.TrailingBlankLine, []},
-        {Credo.Check.Readability.TrailingWhiteSpace, []},
-        {Credo.Check.Readability.UnnecessaryAliasExpansion, []},
-        {Credo.Check.Readability.VariableNames, []},
+          #
+          ## Readability Checks
+          #
+          {Credo.Check.Readability.AliasAs, []},
+          {Credo.Check.Readability.AliasOrder, []},
+          {Credo.Check.Readability.BlockPipe, []},
+          {Credo.Check.Readability.FunctionNames, []},
+          {Credo.Check.Readability.ImplTrue, []},
+          {Credo.Check.Readability.LargeNumbers, []},
+          {Credo.Check.Readability.MaxLineLength, [priority: :low, max_length: 120]},
+          {Credo.Check.Readability.ModuleAttributeNames, []},
+          {Credo.Check.Readability.ModuleDoc, []},
+          {Credo.Check.Readability.ModuleNames, []},
+          {Credo.Check.Readability.OneArityFunctionInPipe, []},
+          {Credo.Check.Readability.ParenthesesInCondition, []},
+          {Credo.Check.Readability.ParenthesesOnZeroArityDefs, []},
+          {Credo.Check.Readability.PipeIntoAnonymousFunctions, []},
+          {Credo.Check.Readability.PredicateFunctionNames, []},
+          {Credo.Check.Readability.PreferImplicitTry, []},
+          {Credo.Check.Readability.RedundantBlankLines, []},
+          {Credo.Check.Readability.Semicolons, []},
+          {Credo.Check.Readability.SeparateAliasRequire, []},
+          {Credo.Check.Readability.SingleFunctionToBlockPipe, []},
+          {Credo.Check.Readability.SinglePipe, []},
+          {Credo.Check.Readability.SpaceAfterCommas, []},
+          {Credo.Check.Readability.StrictModuleLayout, []},
+          {Credo.Check.Readability.StringSigils, []},
+          {Credo.Check.Readability.TrailingBlankLine, []},
+          {Credo.Check.Readability.TrailingWhiteSpace, []},
+          {Credo.Check.Readability.UnnecessaryAliasExpansion, []},
+          {Credo.Check.Readability.VariableNames, []},
+          {Credo.Check.Readability.WithCustomTaggedTuple, []},
+          {Credo.Check.Readability.WithSingleClause, []},
 
-        #
-        ## Refactoring Opportunities
-        #
-        {Credo.Check.Refactor.CondStatements, []},
-        {Credo.Check.Refactor.CyclomaticComplexity, []},
-        {Credo.Check.Refactor.FunctionArity, []},
-        {Credo.Check.Refactor.LongQuoteBlocks, []},
-        {Credo.Check.Refactor.MapInto, false},
-        {Credo.Check.Refactor.MatchInCondition, []},
-        {Credo.Check.Refactor.NegatedConditionsInUnless, []},
-        {Credo.Check.Refactor.NegatedConditionsWithElse, []},
-        {Credo.Check.Refactor.Nesting, []},
-        {Credo.Check.Refactor.UnlessWithElse, []},
-        {Credo.Check.Refactor.WithClauses, []},
+          #
+          ## Refactoring Opportunities
+          #
+          {Credo.Check.Refactor.ABCSize, []},
+          {Credo.Check.Refactor.AppendSingleItem, []},
+          {Credo.Check.Refactor.Apply, []},
+          {Credo.Check.Refactor.CondStatements, []},
+          {Credo.Check.Refactor.CyclomaticComplexity, []},
+          {Credo.Check.Refactor.DoubleBooleanNegation, []},
+          {Credo.Check.Refactor.FilterCount, []},
+          {Credo.Check.Refactor.FilterFilter, []},
+          {Credo.Check.Refactor.FilterReject, []},
+          {Credo.Check.Refactor.FunctionArity, []},
+          {Credo.Check.Refactor.IoPuts, []},
+          {Credo.Check.Refactor.LongQuoteBlocks, []},
+          {Credo.Check.Refactor.MapJoin, []},
+          {Credo.Check.Refactor.MapMap, []},
+          {Credo.Check.Refactor.MatchInCondition, []},
+          {Credo.Check.Refactor.NegatedConditionsInUnless, []},
+          {Credo.Check.Refactor.NegatedConditionsWithElse, []},
+          {Credo.Check.Refactor.NegatedIsNil, []},
+          {Credo.Check.Refactor.Nesting, []},
+          {Credo.Check.Refactor.PassAsyncInTestCases, []},
+          {Credo.Check.Refactor.PipeChainStart, []},
+          {Credo.Check.Refactor.RedundantWithClauseResult, []},
+          {Credo.Check.Refactor.RejectFilter, []},
+          {Credo.Check.Refactor.RejectReject, []},
+          {Credo.Check.Refactor.UnlessWithElse, []},
+          {Credo.Check.Refactor.UtcNowTruncate, []},
+          {Credo.Check.Refactor.WithClauses, []},
 
-        #
-        ## Warnings
-        #
-        {Credo.Check.Warning.ApplicationConfigInModuleAttribute, []},
-        {Credo.Check.Warning.BoolOperationOnSameValues, []},
-        {Credo.Check.Warning.ExpensiveEmptyEnumCheck, []},
-        {Credo.Check.Warning.IExPry, []},
-        {Credo.Check.Warning.IoInspect, []},
-        {Credo.Check.Warning.LazyLogging, false},
-        {Credo.Check.Warning.MixEnv, false},
-        {Credo.Check.Warning.OperationOnSameValues, []},
-        {Credo.Check.Warning.OperationWithConstantResult, []},
-        {Credo.Check.Warning.RaiseInsideRescue, []},
-        {Credo.Check.Warning.UnusedEnumOperation, []},
-        {Credo.Check.Warning.UnusedFileOperation, []},
-        {Credo.Check.Warning.UnusedKeywordOperation, []},
-        {Credo.Check.Warning.UnusedListOperation, []},
-        {Credo.Check.Warning.UnusedPathOperation, []},
-        {Credo.Check.Warning.UnusedRegexOperation, []},
-        {Credo.Check.Warning.UnusedStringOperation, []},
-        {Credo.Check.Warning.UnusedTupleOperation, []},
-        {Credo.Check.Warning.UnsafeExec, []},
+          #
+          ## Warnings
+          #
+          {Credo.Check.Consistency.UnusedVariableNames, []},
+          {Credo.Check.Warning.ApplicationConfigInModuleAttribute, []},
+          {Credo.Check.Warning.BoolOperationOnSameValues, []},
+          {Credo.Check.Warning.Dbg, []},
+          {Credo.Check.Warning.ExpensiveEmptyEnumCheck, []},
+          {Credo.Check.Warning.IExPry, []},
+          {Credo.Check.Warning.IoInspect, []},
+          {Credo.Check.Warning.LazyLogging, false},
+          {Credo.Check.Warning.LeakyEnvironment, []},
+          {Credo.Check.Warning.MapGetUnsafePass, []},
+          {Credo.Check.Warning.MissedMetadataKeyInLoggerConfig, []},
+          {Credo.Check.Warning.MixEnv, []},
+          {Credo.Check.Warning.OperationOnSameValues, []},
+          {Credo.Check.Warning.OperationWithConstantResult, []},
+          {Credo.Check.Warning.RaiseInsideRescue, []},
+          {Credo.Check.Warning.SpecWithStruct, []},
+          {Credo.Check.Warning.UnsafeExec, []},
+          {Credo.Check.Warning.UnsafeToAtom, []},
+          {Credo.Check.Warning.UnusedEnumOperation, []},
+          {Credo.Check.Warning.UnusedFileOperation, []},
+          {Credo.Check.Warning.UnusedKeywordOperation, []},
+          {Credo.Check.Warning.UnusedListOperation, []},
+          {Credo.Check.Warning.UnusedPathOperation, []},
+          {Credo.Check.Warning.UnusedRegexOperation, []},
+          {Credo.Check.Warning.UnusedStringOperation, []},
+          {Credo.Check.Warning.UnusedTupleOperation, []},
+          {Credo.Check.Warning.WrongTestFileExtension, []}
+        ],
+        disabled: [
+          #
+          # Controversial and experimental checks (opt-in, just move the check to `:enabled`
+          #   and be sure to use `mix credo --strict` to see low priority checks)
+          #
+          {Credo.Check.Readability.MultiAlias, []},
+          {Credo.Check.Readability.NestedFunctionCalls, []},
+          {Credo.Check.Readability.OnePipePerLine, []},
+          {Credo.Check.Readability.Specs, []},
+          {Credo.Check.Refactor.ModuleDependencies, []},
+          {Credo.Check.Refactor.VariableRebinding, []}
 
-        #
-        # Checks scheduled for next check update (opt-in for now, just replace `false` with `[]`)
+          # {Credo.Check.Refactor.MapInto, []},
 
-        #
-        # Controversial and experimental checks (opt-in, just replace `false` with `[]`)
-        #
-        {Credo.Check.Consistency.MultiAliasImportRequireUse, []},
-        {Credo.Check.Consistency.UnusedVariableNames, []},
-        {Credo.Check.Design.DuplicatedCode, []},
-        {Credo.Check.Readability.AliasAs, []},
-        {Credo.Check.Readability.BlockPipe, []},
-        {Credo.Check.Readability.ImplTrue, []},
-        {Credo.Check.Readability.MultiAlias, false},
-        {Credo.Check.Readability.SeparateAliasRequire, []},
-        {Credo.Check.Readability.SinglePipe, []},
-        {Credo.Check.Readability.Specs, false},
-        {Credo.Check.Readability.StrictModuleLayout, []},
-        {Credo.Check.Readability.WithCustomTaggedTuple, []},
-        {Credo.Check.Refactor.ABCSize, []},
-        {Credo.Check.Refactor.AppendSingleItem, []},
-        {Credo.Check.Refactor.DoubleBooleanNegation, []},
-        {Credo.Check.Refactor.ModuleDependencies, false},
-        {Credo.Check.Refactor.NegatedIsNil, []},
-        {Credo.Check.Refactor.PipeChainStart, []},
-        {Credo.Check.Refactor.VariableRebinding, false},
-        {Credo.Check.Warning.LeakyEnvironment, []},
-        {Credo.Check.Warning.MapGetUnsafePass, []},
-        {Credo.Check.Warning.UnsafeToAtom, []}
-
-        #
-        # Custom checks can be created using `mix credo.gen.check`.
-        #
-      ]
+          #
+          # Custom checks can be created using `mix credo.gen.check`.
+          #
+        ]
+      }
     }
   ]
 }
diff --git a/.dialyzer_ignore.exs b/.dialyzer_ignore.exs
index 23fc3f6..ca73353 100644
--- a/.dialyzer_ignore.exs
+++ b/.dialyzer_ignore.exs
@@ -1,5 +1,3 @@
 [
-  {"lib/poison/encoder.ex", :unknown_function, 80},
-  {"lib/poison/decoder.ex", :unknown_function, 106},
   {"lib/poison/parser.ex", :improper_list_constr}
 ]
diff --git a/.formatter.exs b/.formatter.exs
index 818a3c4..3d57b78 100644
--- a/.formatter.exs
+++ b/.formatter.exs
@@ -2,7 +2,7 @@
 [
   import_deps: [:stream_data],
   inputs: [
-    "{mix,.credo,.formatter}.exs",
-    "{config,lib,test,bench,profile}/**/*.{ex,exs}"
+    "{.credo,.dialyzer_ignore,.formatter,mix}.exs",
+    "{config,bench,lib,profile,test}/**/*.{ex,exs}"
   ]
 ]
diff --git a/.gitattributes b/.gitattributes
new file mode 100644
index 0000000..6313b56
--- /dev/null
+++ b/.gitattributes
@@ -0,0 +1 @@
+* text=auto eol=lf
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 6b734e4..66adb94 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -4,6 +4,7 @@ on:
   push:
     branches:
       - master
+      - develop
   pull_request:
     branches:
       - master
@@ -18,30 +19,32 @@ jobs:
     strategy:
       matrix:
         os:
-          - ubuntu-latest
-          - windows-latest
+          - ubuntu-22.04
           - windows-2022
-          - macos-11
         otp:
-          - '24.1'
-          - '24.0'
-          - '23.3'
-          - '23.2'
-          - '23.1'
-          - '23.0'
+          - "26.2.2"
+          - "25.3.2"
+          - "24.3.4"
         elixir:
-          - '1.12.3'
-          - '1.12.2'
-          - '1.12.1'
-          - '1.12.0'
-          - '1.11.4'
-          - '1.11.3'
-          - '1.11.2'
-          - '1.11.1'
-          - '1.11.0'
+          - "1.16.3"
+          - "1.15.7"
+          - "1.14.5"
+          - "1.13.4"
+          - "1.12.3"
+        exclude:
+          - otp: "26.2.2"
+            elixir: "1.14.5"
+          - otp: "26.2.2"
+            elixir: "1.13.4"
+          - otp: "26.2.2"
+            elixir: "1.12.3"
+          - otp: "25.3.2"
+            elixir: "1.13.4"
+          - otp: "25.3.2"
+            elixir: "1.12.3"
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
         with:
           fetch-depth: 0
           submodules: true
@@ -51,8 +54,8 @@ jobs:
           otp-version: ${{matrix.otp}}
           elixir-version: ${{matrix.elixir}}
 
-      - uses: actions/cache@v2
-        id: mix-cache
+      - uses: actions/cache@v4
+        id: cache
         with:
           path: |
             _build
@@ -60,7 +63,7 @@ jobs:
             vendor
           key: ${{ runner.os }}-${{ matrix.otp }}-${{ matrix.elixir }}-${{ hashFiles('mix.lock') }}
 
-      - if: steps.mix-cache.outputs.cache-hit != 'true'
+      - if: steps.cache.outputs.cache-hit != 'true'
         run: mix deps.get
 
       - run: mix coveralls.github
diff --git a/.gitignore b/.gitignore
index 9a1fb79..760631d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -22,8 +22,8 @@ erl_crash.dump
 # Ignore package tarball (built via "mix hex.build").
 poison-*.tar
 
-# Temporary files for e.g. tests
-/tmp
+# Temporary files, for example, from tests.
+/tmp/
 
 .elixir_ls
 *.benchee
diff --git a/.tool-versions b/.tool-versions
index 9a98889..736ecce 100644
--- a/.tool-versions
+++ b/.tool-versions
@@ -1,2 +1,2 @@
-erlang 24.1.7
-elixir 1.13.0-rc.1-otp-24
+erlang 27.0
+elixir 1.17.0-rc.1-otp-27
diff --git a/.vscode/settings.json b/.vscode/settings.json
index 8dc16ad..9e5db87 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -1,9 +1,5 @@
 {
   "editor.formatOnSave": true,
-  "editor.formatOnType": true,
-  "files.watcherExclude": {
-    "**/target": true
-  },
   "elixirLS.enableTestLenses": true,
   "elixirLS.dialyzerWarnOpts": ["no_improper_lists"]
 }
diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
index 0000000..6f0fcde
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,39 @@
+# Poison Changelog
+
+## v6.0.0
+
+### Features
+
+* Support Erlang 27 and Elixir 1.17
+    [#214](https://github.com/devinus/poison/issues/214)
+    [#222](https://github.com/devinus/poison/issues/222)
+* Reintroduce `Poison.encode_to_iodata!/1` for Phoenix compatibility
+    [#172](https://github.com/devinus/poison/issues/172)
+    [#206](https://github.com/devinus/poison/pull/206)
+* Make [`:html_safe`](`t:Poison.Encoder.escape/0`) encode option follow OWASP
+  recommended HTML escaping
+    [#194](https://github.com/devinus/poison/issues/194)
+* Add `Date.Range` encoding
+* Allow [`:as`](`t:Poison.Decoder.as/0`) decode option to be a function
+    [#207](https://github.com/devinus/poison/pull/207)
+* Add a [CHANGELOG](CHANGELOG.md)
+    [#105](https://github.com/devinus/poison/issues/105)
+
+### Bug Fixes
+
+* Stop double decoding structs
+    [#191](https://github.com/devinus/poison/issues/191)
+* Fix various typespecs
+    [#199](https://github.com/devinus/poison/issues/199)
+* Correctly encode some UTF-8 surrogate pairs
+    [#217](https://github.com/devinus/poison/issues/217)
+
+### Performance Improvements
+
+* Significantly improve performance
+    ([2024-06-06](https://gist.github.com/devinus/afb351ae45194a6b93b6db9bf2d4c163))
+
+### Breaking Changes
+
+* Remove deprecated `HashSet` encoding
+* Minimum supported versions are now Erlang 24 and Elixir 1.12
diff --git a/Dockerfile b/Dockerfile
index aaf480f..6eaed46 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM elixir:1.12.3-alpine as base
+FROM elixir:1.17.0-rc.0-otp-27-alpine AS base
 ARG MIX_ENV
 ENV MIX_ENV ${MIX_ENV:-test}
 RUN apk --no-cache add git build-base
diff --git a/LICENSE b/LICENSE
index 5f1897d..62b6630 100644
--- a/LICENSE
+++ b/LICENSE
@@ -1,4 +1,6 @@
-Copyright (C) 2021 Devin Alexander Torres <d@devinus.io>
+BSD Zero Clause License
+
+Copyright (C) 2024 Devin Alexander Torres <d@devinus.io>
 
 Permission to use, copy, modify, and/or distribute this software for any
 purpose with or without fee is hereby granted.
diff --git a/README.md b/README.md
index bf49a99..f9fb9fd 100644
--- a/README.md
+++ b/README.md
@@ -1,9 +1,10 @@
 # Poison
 
-[![Build Status](https://img.shields.io/github/workflow/status/devinus/poison/ci/master)](https://github.com/devinus/poison/actions/workflows/ci.yml)
-[![Coverage Status](https://img.shields.io/coveralls/github/devinus/poison/master)](https://coveralls.io/github/devinus/poison?branch=master)
-[![Hex.pm Version](https://img.shields.io/hexpm/v/poison.svg?style=flat-square)](https://hex.pm/packages/poison)
-[![Hex.pm Download Total](https://img.shields.io/hexpm/dt/poison.svg?style=flat-square)](https://hex.pm/packages/poison)
+[![Build Status](https://img.shields.io/github/actions/workflow/status/devinus/poison/ci.yml)](https://github.com/devinus/poison/actions/workflows/ci.yml)
+[![Coverage Status](https://img.shields.io/coverallsCoverage/github/devinus/poison)](https://coveralls.io/github/devinus/poison?branch=master))
+[![Hex.pm Version](https://img.shields.io/hexpm/v/poison)](https://hex.pm/packages/poison)
+[![Hex.pm Download Total](https://img.shields.io/hexpm/dt/poison)](https://hex.pm/packages/poison)
+[![Hex.pm Dependents](https://img.shields.io/librariesio/dependents/hex/poison)](https://hex.pm/packages/poison)
 
 Poison is a new JSON library for Elixir focusing on wicked-fast **speed**
 without sacrificing **simplicity**, **completeness**, or **correctness**.
@@ -17,7 +18,7 @@ several techniques that are [known to benefit BeamAsm][2] for JIT compilation,
 Poison benchmarks sometimes puts Poison's performance close to `jiffy` and
 usually faster than other Erlang/Elixir libraries.
 
-Poison fully conforms to [RFC 7159][4], [ECMA 404][5], and fully passes the
+Poison fully conforms to [RFC 8259][4], [ECMA 404][5], and fully passes the
 [JSONTestSuite][6].
 
 ## Installation
@@ -32,8 +33,8 @@ end
 
 Then, update your dependencies:
 
-```sh-session
-$ mix deps.get
+```sh
+mix deps.get
 ```
 
 ## Usage
@@ -133,7 +134,7 @@ ignored.
 
 ### Key Validation
 
-According to [RFC 7159][4] keys in a JSON object should be unique. This is
+According to [RFC 8259][4] keys in a JSON object should be unique. This is
 enforced and resolved in different ways in other libraries. In the Ruby JSON
 library for example, the output generated from encoding a hash with a duplicate
 key (say one is a string, the other an atom) will include both keys. When
@@ -154,16 +155,16 @@ iex> Poison.encode!(%{:foo => "foo1", "foo" => "foo2"}, strict_keys: true)
 
 ## Benchmarking
 
-```sh-session
-$ MIX_ENV=bench mix run bench/run.exs
+```sh
+MIX_ENV=bench mix run bench/run.exs
 ```
 
 ### Current Benchmarks
 
-As of 2021-07-22:
+As of 2024-06-06:
 
-- Amazon EC2 c5.2xlarge instance running Ubuntu Server 20.04:
-  https://gist.github.com/devinus/f56cff9e5a0aa9de9215cf33212085f6
+- Amazon EC2 c6i.2xlarge instance running Ubuntu Server 22.04:
+  <https://gist.github.com/devinus/afb351ae45194a6b93b6db9bf2d4c163>
 
 ## License
 
@@ -171,10 +172,10 @@ Poison is released under the [public-domain-equivalent][8] [0BSD][9] license.
 
 [1]: https://erlang.org/euc/07/papers/1700Gustafsson.pdf
 [2]: https://erlang.org/documentation/doc-12.0-rc1/erts-12.0/doc/html/BeamAsm.html
-[3]: http://jlouisramblings.blogspot.com/2013/07/problematic-traits-in-erlang.html
-[4]: https://tools.ietf.org/html/rfc7159
-[5]: http://www.ecma-international.org/publications/files/ECMA-ST/ECMA-404.pdf
+[3]: https://jlouisramblings.blogspot.com/2013/07/problematic-traits-in-erlang.html
+[4]: https://datatracker.ietf.org/doc/html/rfc8259
+[5]: https://ecma-international.org/wp-content/uploads/ECMA-404_2nd_edition_december_2017.pdf
 [6]: https://github.com/nst/JSONTestSuite
-[7]: http://prog21.dadgum.com/70.html
+[7]: https://prog21.dadgum.com/70.html
 [8]: https://en.wikipedia.org/wiki/Public-domain-equivalent_license
 [9]: https://opensource.org/licenses/0BSD
diff --git a/bench/run.exs b/bench/run.exs
index 962c238..ef918dd 100644
--- a/bench/run.exs
+++ b/bench/run.exs
@@ -1,13 +1,16 @@
 defmodule Bench do
-  alias Benchee.Formatters.{Console, HTML}
+  alias Benchee.Formatters.{Console, HTML, Markdown}
 
   def run_decode do
     Benchee.run(decode_jobs(),
-      parallel: 8,
+      title: "Decode",
+      parallel: 4,
       warmup: 1,
       time: 10,
       memory_time: 1,
+      reduction_time: 1,
       pre_check: true,
+      measure_function_call_overhead: true,
       load: Path.join(__DIR__, "decode.benchee"),
       save: [path: Path.join(__DIR__, "decode.benchee")],
       inputs:
@@ -16,21 +19,24 @@ defmodule Bench do
           |> read_data()
           |> (&{name, &1}).()
         end,
-      before_each: fn input -> :binary.copy(input) end,
       formatters: [
         {Console, extended_statistics: true},
-        {HTML, extended_statistics: true, file: Path.expand("output/decode.html", __DIR__)}
+        {Markdown, file: Path.expand("output/decode.md", __DIR__)},
+        {HTML, auto_open: false, file: Path.expand("output/decode.html", __DIR__)}
       ]
     )
   end
 
   def run_encode do
     Benchee.run(encode_jobs(),
-      parallel: 8,
+      title: "Encode",
+      parallel: 4,
       warmup: 1,
       time: 10,
       memory_time: 1,
+      reduction_time: 1,
       pre_check: true,
+      measure_function_call_overhead: true,
       load: Path.join(__DIR__, "encode.benchee"),
       save: [path: Path.join(__DIR__, "encode.benchee")],
       inputs:
@@ -42,7 +48,8 @@ defmodule Bench do
         end,
       formatters: [
         {Console, extended_statistics: true},
-        {HTML, extended_statistics: true, file: Path.expand("output/encode.html", __DIR__)}
+        {Markdown, file: Path.expand("output/encode.md", __DIR__)},
+        {HTML, auto_open: false, file: Path.expand("output/encode.html", __DIR__)}
       ]
     )
   end
@@ -58,27 +65,39 @@ defmodule Bench do
   end
 
   defp decode_jobs do
-    %{
+    jobs = %{
       "Jason" => &Jason.decode!/1,
       "jiffy" => &:jiffy.decode(&1, [:return_maps, :use_nil]),
-      "JSON" => &JSON.decode!/1,
-      "jsone" => &:jsone.decode/1,
+      "jsone" => &:jsone.decode(&1, [:reject_invalid_utf8, duplicate_map_keys: :last]),
       "JSX" => &JSX.decode!(&1, [:strict]),
       "Poison" => &Poison.Parser.parse!/1,
-      "Tiny" => &Tiny.decode!/1
+      "Tiny" => &Tiny.decode!/1,
+      "Thoas" => &:thoas.decode/1
     }
+
+    if Code.ensure_loaded?(:json) do
+      Map.put(jobs, "json", &:json.decode/1)
+    else
+      jobs
+    end
   end
 
   defp encode_jobs do
-    %{
-      "Jason" => &Jason.encode!/1,
+    jobs = %{
+      "Jason" => &Jason.encode_to_iodata!/1,
       "jiffy" => &:jiffy.encode(&1, [:use_nil]),
-      "JSON" => &JSON.encode!/1,
       "jsone" => &:jsone.encode/1,
-      "JSX" => &JSX.encode!/1,
-      "Poison" => &Poison.encode!/1,
-      "Tiny" => &Tiny.encode!/1
+      "JSX" => &JSX.encode!(&1, [:strict]),
+      "Poison" => &Poison.encode_to_iodata!/1,
+      "Tiny" => &Tiny.encode_to_iodata!/1,
+      "Thoas" => &:thoas.encode_to_iodata/1
     }
+
+    if Code.ensure_loaded?(:json) do
+      Map.put(jobs, "json", &:json.encode/1)
+    else
+      jobs
+    end
   end
 
   defp decode_inputs do
diff --git a/docker-compose.yml b/docker-compose.yml
index e924c52..5740b98 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -1,4 +1,3 @@
-version: "3.7"
 services:
   project:
     build:
diff --git a/lib/poison.ex b/lib/poison.ex
index bb07476..381f29d 100644
--- a/lib/poison.ex
+++ b/lib/poison.ex
@@ -9,39 +9,75 @@ defmodule Poison do
   alias Poison.{ParseError, Parser}
 
   @doc """
-  Encode a value to JSON.
+  Encode a value to JSON IO data.
 
-      iex> Poison.encode([1, 2, 3])
-      {:ok, "[1,2,3]"}
+      iex> Poison.encode_to_iodata([1, 2, 3])
+      {:ok, [91, ["1", 44, "2", 44, "3"], 93]}
+
+      iex> Poison.encode_to_iodata({})
+      {:error, %Poison.EncodeError{message: nil, value: {}}}
   """
-  @spec encode(Encoder.t(), Encoder.options()) ::
-          {:ok, iodata}
-          | {:error, Exception.t()}
-  def encode(value, options \\ %{}) do
-    {:ok, encode!(value, options)}
+  @spec encode_to_iodata(Encoder.t()) :: {:ok, iodata} | {:error, EncodeError.t()}
+  @spec encode_to_iodata(Encoder.t(), Encoder.options() | [Encoder.option()]) ::
+          {:ok, iodata} | {:error, EncodeError.t()}
+  def encode_to_iodata(value, options \\ %{}) do
+    {:ok, encode_to_iodata!(value, options)}
   rescue
     exception in [EncodeError] ->
       {:error, exception}
   end
 
   @doc """
-  Encode a value to JSON as iodata.
+  Encode a value to JSON IO data. Raises an exception on error.
 
-      iex> Poison.encode_to_iodata([1, 2, 3])
-      {:ok, [91, ["1", 44, "2", 44, "3"], 93]}
+      iex> Poison.encode_to_iodata!([1, 2, 3])
+      [91, ["1", 44, "2", 44, "3"], 93]
+
+      iex> Poison.encode_to_iodata!({})
+      ** (Poison.EncodeError) unable to encode value: {}
   """
-  @spec encode_to_iodata(Encoder.t, Keyword.t) :: {:ok, iodata} | {:error, {:invalid, any}}
-  def encode_to_iodata(value, options \\ []) do
-    encode(value, [iodata: true] ++ options)
+  @spec encode_to_iodata!(Encoder.t()) :: iodata
+  @spec encode_to_iodata!(Encoder.t(), Encoder.options() | [Encoder.option()]) :: iodata
+  def encode_to_iodata!(value, options \\ %{})
+
+  def encode_to_iodata!(value, options) when is_list(options) do
+    encode_to_iodata!(value, Map.new(options))
+  end
+
+  def encode_to_iodata!(value, options) do
+    Encoder.encode(value, options)
   end
 
   @doc """
-  Encode a value to JSON, raises an exception on error.
+  Encode a value to JSON.
+
+      iex> Poison.encode([1, 2, 3])
+      {:ok, "[1,2,3]"}
+
+      iex> Poison.encode({})
+      {:error, %Poison.EncodeError{message: nil, value: {}}}
+  """
+  @spec encode(Encoder.t()) :: {:ok, iodata} | {:error, EncodeError.t()}
+  @spec encode(Encoder.t(), Encoder.options() | [Encoder.option()]) ::
+          {:ok, iodata} | {:error, EncodeError.t()}
+  def encode(value, options \\ %{}) do
+    {:ok, encode!(value, options)}
+  rescue
+    exception in [EncodeError] ->
+      {:error, exception}
+  end
+
+  @doc """
+  Encode a value to JSON. Raises an exception on error.
 
       iex> Poison.encode!([1, 2, 3])
       "[1,2,3]"
+
+      iex> Poison.encode!({})
+      ** (Poison.EncodeError) unable to encode value: {}
   """
-  @spec encode!(Encoder.t(), Encoder.options()) :: iodata | no_return
+  @spec encode!(Encoder.t()) :: binary
+  @spec encode!(Encoder.t(), Encoder.options() | [Encoder.option()]) :: binary
   def encode!(value, options \\ %{})
 
   def encode!(value, options) when is_list(options) do
@@ -49,22 +85,7 @@ defmodule Poison do
   end
 
   def encode!(value, options) do
-    if options[:iodata] do
-      Encoder.encode(value, options)
-    else
-      value |> Encoder.encode(options) |> IO.iodata_to_binary()
-    end
-  end
-
-  @doc """
-  Encode a value to JSON as iodata, raises an exception on error.
-
-      iex> Poison.encode_to_iodata!([1, 2, 3])
-      [91, ["1", 44, "2", 44, "3"], 93]
-  """
-  @spec encode_to_iodata!(Encoder.t, Keyword.t) :: iodata | no_return
-  def encode_to_iodata!(value, options \\ []) do
-    encode!(value, [iodata: true] ++ options)
+    value |> encode_to_iodata!(options) |> IO.iodata_to_binary()
   end
 
   @doc """
@@ -72,13 +93,13 @@ defmodule Poison do
 
       iex> Poison.decode("[1,2,3]")
       {:ok, [1, 2, 3]}
+
+      iex> Poison.decode("[")
+      {:error, %Poison.ParseError{data: "[", skip: 1, value: nil}}
   """
-  @spec decode(iodata) ::
-          {:ok, Parser.t()}
-          | {:error, Exception.t()}
-  @spec decode(iodata, Decoder.options()) ::
-          {:ok, Parser.t()}
-          | {:error, Exception.t()}
+  @spec decode(iodata) :: {:ok, Parser.t()} | {:error, ParseError.t() | DecodeError.t()}
+  @spec decode(iodata, Decoder.options() | [Decoder.option()]) ::
+          {:ok, Decoder.t()} | {:error, ParseError.t() | DecodeError.t()}
   def decode(iodata, options \\ %{}) do
     {:ok, decode!(iodata, options)}
   rescue
@@ -87,17 +108,18 @@ defmodule Poison do
   end
 
   @doc """
-  Decode JSON to a value, raises an exception on error.
+  Decode JSON to a value. Raises an exception on error.
 
       iex> Poison.decode!("[1,2,3]")
       [1, 2, 3]
+
+      iex> Poison.decode!("[")
+      ** (Poison.ParseError) unexpected end of input at position 1
   """
-  @spec decode!(iodata) :: Parser.t() | no_return
-  def decode!(value) do
-    Parser.parse!(value, %{})
-  end
+  @spec decode!(iodata) :: Parser.t()
+  @spec decode!(iodata, Decoder.options() | [Decoder.option()]) :: Decoder.t()
+  def decode!(value, options \\ %{})
 
-  @spec decode!(iodata, Decoder.options()) :: Decoder.t() | no_return
   def decode!(value, options) when is_list(options) do
     decode!(value, Map.new(options))
   end
@@ -106,7 +128,6 @@ defmodule Poison do
     value
     |> Parser.parse!(options)
     |> Decode.transform(options)
-    |> Decoder.decode(options)
   end
 
   def decode!(value, options) do
diff --git a/lib/poison/decoder.ex b/lib/poison/decoder.ex
index 47055e9..9d607fe 100644
--- a/lib/poison/decoder.ex
+++ b/lib/poison/decoder.ex
@@ -17,6 +17,9 @@ defmodule Poison.Decode do
 
   alias Poison.Decoder
 
+  @compile :inline
+  @compile :inline_list_funcs
+
   def transform(value, options) when is_map(value) or is_list(value) do
     case Map.get(options, :as) do
       nil -> value
@@ -110,16 +113,16 @@ end
 defprotocol Poison.Decoder do
   @fallback_to_any true
 
-  @typep as :: map | struct | [as] | (t -> as | [as])
+  @type keys :: :atoms | :atoms!
+  @type decimal :: boolean
+  @type as :: map | struct | [as] | (t -> as)
 
-  @typep option :: {:keys, :atoms | :atoms!} | {:decimal, boolean} | {:as, as}
-  @type options ::
-          %{
-            optional(:keys) => :atoms | :atoms!,
-            optional(:decimal) => boolean,
-            optional(:as) => as
-          }
-          | [option]
+  @type option :: {:keys, keys} | {:decimal, decimal} | {:as, as}
+  @type options :: %{
+          optional(:keys) => keys,
+          optional(:decimal) => decimal,
+          optional(:as) => as
+        }
 
   @spec decode(t, options) :: any
   def decode(value, options)
diff --git a/lib/poison/encoder.ex b/lib/poison/encoder.ex
index 30b4910..0c6bf3c 100644
--- a/lib/poison/encoder.ex
+++ b/lib/poison/encoder.ex
@@ -80,11 +80,18 @@ end
 defprotocol Poison.Encoder do
   @fallback_to_any true
 
-  @typep escape :: :unicode | :javascript | :html_safe
-  @typep pretty :: boolean
-  @typep indent :: non_neg_integer
-  @typep offset :: non_neg_integer
-  @typep strict_keys :: boolean
+  @type escape :: :unicode | :javascript | :html_safe
+  @type pretty :: boolean
+  @type indent :: non_neg_integer
+  @type offset :: non_neg_integer
+  @type strict_keys :: boolean
+
+  @type option ::
+          {:escape, escape}
+          | {:pretty, pretty}
+          | {:indent, indent}
+          | {:offset, offset}
+          | {:strict_keys, strict_keys}
 
   @type options :: %{
           optional(:escape) => escape,
@@ -130,7 +137,7 @@ defimpl Poison.Encoder, for: BitString do
     end
   end
 
-  # http://en.wikipedia.org/wiki/Unicode_control_characters
+  # https://en.wikipedia.org/wiki/Unicode_control_characters
   defp escape(<<char, rest::bits>>, mode) when char <= 0x1F or char == 0x7F do
     [seq(char) | escape(rest, mode)]
   end
@@ -147,8 +154,8 @@ defimpl Poison.Encoder, for: BitString do
     [seq(char) | escape(rest, :unicode)]
   end
 
-  # http://en.wikipedia.org/wiki/UTF-16#Example_UTF-16_encoding_procedure
-  # http://unicodebook.readthedocs.org/unicode_encodings.html
+  # https://en.wikipedia.org/wiki/UTF-16#U+D800_to_U+DFFF_(surrogates)
+  # https://unicodebook.readthedocs.io/unicode_encodings.html
   defp escape(<<char::utf8, rest::bits>>, :unicode) when char > 0xFFFF do
     code = char - 0x10000
 
@@ -159,13 +166,28 @@ defimpl Poison.Encoder, for: BitString do
     ]
   end
 
-  defp escape(<<char::utf8, rest::bits>>, mode)
-       when mode in [:html_safe, :javascript] and char in [0x2028, 0x2029] do
-    [seq(char) | escape(rest, mode)]
+  # https://cheatsheetseries.owasp.org/cheatsheets/Cross_Site_Scripting_Prevention_Cheat_Sheet.html
+  # https://rubydoc.info/docs/rails/ActiveSupport%2FJSON%2FEncoding%2Eescape_html_entities_in_json=
+  defp escape(<<?&::utf8, rest::bits>>, :html_safe) do
+    ["\\u0026" | escape(rest, :html_safe)]
+  end
+
+  defp escape(<<?<::utf8, rest::bits>>, :html_safe) do
+    ["\\u003C" | escape(rest, :html_safe)]
+  end
+
+  defp escape(<<?>::utf8, rest::bits>>, :html_safe) do
+    ["\\u003E" | escape(rest, :html_safe)]
   end
 
-  defp escape(<<?/::utf8, rest::bits>>, :html_safe) do
-    ["\\/" | escape(rest, :html_safe)]
+  defp escape(<<"\u2028"::utf8, rest::bits>>, mode)
+       when mode in [:html_safe, :javascript] do
+    ["\\u2028" | escape(rest, mode)]
+  end
+
+  defp escape(<<"\u2029"::utf8, rest::bits>>, mode)
+       when mode in [:html_safe, :javascript] do
+    ["\\u2029" | escape(rest, mode)]
   end
 
   defp escape(string, mode) do
@@ -177,11 +199,11 @@ defimpl Poison.Encoder, for: BitString do
   @compile {:inline, chunk_size: 3}
 
   defp chunk_size(<<char, _rest::bits>>, _mode, acc)
-       when char <= 0x1F or char in '"\\' do
+       when char <= 0x1F or char in ~c("\\) do
     acc
   end
 
-  defp chunk_size(<<?/, _rest::bits>>, :html_safe, acc) do
+  defp chunk_size(<<char, _rest::bits>>, :html_safe, acc) when char in ~c(&<>) do
     acc
   end
 
@@ -189,7 +211,7 @@ defimpl Poison.Encoder, for: BitString do
     chunk_size(rest, mode, acc + 1)
   end
 
-  defp chunk_size(<<_::utf8, _rest::bits>>, :unicode, acc) do
+  defp chunk_size(<<_codepoint::utf8, _rest::bits>>, :unicode, acc) do
     acc
   end
 
@@ -199,7 +221,7 @@ defimpl Poison.Encoder, for: BitString do
   end
 
   defp chunk_size(<<codepoint::utf8, rest::bits>>, mode, acc) do
-    chunk_size(rest, mode, acc + byte_size(<<codepoint::utf8>>))
+    chunk_size(rest, mode, acc + codepoint_size(codepoint))
   end
 
   defp chunk_size(<<>>, _mode, acc), do: acc
@@ -218,6 +240,16 @@ defimpl Poison.Encoder, for: BitString do
       s -> ["\\u" | s]
     end
   end
+
+  @compile {:inline, codepoint_size: 1}
+
+  defp codepoint_size(codepoint) do
+    cond do
+      codepoint <= 0x7FF -> 2
+      codepoint <= 0xFFFF -> 3
+      true -> 4
+    end
+  end
 end
 
 defimpl Poison.Encoder, for: Integer do
@@ -240,7 +272,7 @@ defimpl Poison.Encoder, for: Map do
   @compile :inline
   @compile :inline_list_funcs
 
-  def encode(map, _) when map_size(map) < 1, do: "{}"
+  def encode(map, _options) when map_size(map) < 1, do: "{}"
 
   def encode(map, options) do
     map
@@ -347,7 +379,7 @@ defimpl Poison.Encoder, for: List do
   end
 end
 
-defimpl Poison.Encoder, for: [Range, Stream, MapSet, HashSet, Date.Range] do
+defimpl Poison.Encoder, for: [Range, Stream, MapSet, Date.Range] do
   alias Poison.{Encoder, Pretty}
 
   use Pretty
diff --git a/lib/poison/parser.ex b/lib/poison/parser.ex
index 5e5f2de..cad8ba6 100644
--- a/lib/poison/parser.ex
+++ b/lib/poison/parser.ex
@@ -30,7 +30,7 @@ defmodule Poison.ParseError do
       <<>> ->
         "unexpected end of input at position #{pos}"
 
-      <<token::utf8, _::bits>> ->
+      <<token::utf8, _rest::bits>> ->
         "unexpected token at position #{pos}: #{escape(token)}"
 
       _rest ->
@@ -50,31 +50,28 @@ end
 
 defmodule Poison.Parser do
   @moduledoc """
-  An RFC 7159 and ECMA 404 conforming JSON parser.
+  An RFC 8259 and ECMA 404 conforming JSON parser.
 
-  See: https://tools.ietf.org/html/rfc7159
-  See: http://www.ecma-international.org/publications/files/ECMA-ST/ECMA-404.pdf
+  See: https://datatracker.ietf.org/doc/html/rfc8259
+  See: https://ecma-international.org/wp-content/uploads/ECMA-404_2nd_edition_december_2017.pdf
   """
 
   @compile :inline
   @compile :inline_list_funcs
-  @compile {:inline_effort, 2500}
-  @compile {:inline_size, 150}
-  @compile {:inline_unroll, 3}
 
   import Bitwise
 
   alias Poison.{Decoder, ParseError}
 
-  @typep value :: nil | true | false | map | list | float | integer | String.t()
+  @type scalar :: nil | true | false | float | integer | String.t()
 
   if Code.ensure_loaded?(Decimal) do
-    @type t :: value | Decimal.t()
+    @type t :: scalar | Decimal.t() | [t] | %{optional(String.t()) => t}
   else
-    @type t :: value
+    @type t :: scalar | [t] | %{optional(String.t()) => t}
   end
 
-  whitespace = '\s\t\n\r'
+  whitespace = ~c"\s\t\n\r"
   digits = ?0..?9
 
   defmacrop syntax_error(skip) do
@@ -83,14 +80,14 @@ defmodule Poison.Parser do
     end
   end
 
-  @spec parse!(iodata | binary, Decoder.options()) :: t | no_return
+  @spec parse!(iodata, Decoder.options()) :: t
   def parse!(value, options \\ %{})
 
   def parse!(data, options) when is_bitstring(data) do
     [value | skip] =
       value(data, data, :maps.get(:keys, options, nil), :maps.get(:decimal, options, nil), 0)
 
-    <<_::binary-size(skip), rest::bits>> = data
+    <<_skip::binary-size(skip), rest::bits>> = data
     skip_whitespace(rest, skip, value)
   rescue
     exception in ParseError ->
@@ -105,25 +102,16 @@ defmodule Poison.Parser do
 
   @compile {:inline, value: 5}
 
-  defp value(<<?f, rest::bits>>, _data, _keys, _decimal, skip) do
-    case rest do
-      <<"alse", _rest::bits>> -> [false | skip + 5]
-      _other -> syntax_error(skip)
-    end
+  defp value(<<"null", _rest::bits>>, _data, _keys, _decimal, skip) do
+    [nil | skip + 4]
   end
 
-  defp value(<<?t, rest::bits>>, _data, _keys, _decimal, skip) do
-    case rest do
-      <<"rue", _rest::bits>> -> [true | skip + 4]
-      _other -> syntax_error(skip)
-    end
+  defp value(<<"true", _rest::bits>>, _data, _keys, _decimal, skip) do
+    [true | skip + 4]
   end
 
-  defp value(<<?n, rest::bits>>, _data, _keys, _decimal, skip) do
-    case rest do
-      <<"ull", _rest::bits>> -> [nil | skip + 4]
-      _other -> syntax_error(skip)
-    end
+  defp value(<<"false", _rest::bits>>, _data, _keys, _decimal, skip) do
+    [false | skip + 5]
   end
 
   defp value(<<?-, rest::bits>>, _data, _keys, decimal, skip) do
@@ -192,10 +180,10 @@ defmodule Poison.Parser do
   defp object_pairs(<<?", rest::bits>>, data, keys, decimal, skip, acc) do
     start = skip + 1
     [name | skip] = string_continue(rest, data, start)
-    <<_::binary-size(skip), rest::bits>> = data
+    <<_skip::binary-size(skip), rest::bits>> = data
 
     [value | skip] = object_value(rest, data, keys, decimal, skip)
-    <<_::binary-size(skip), rest::bits>> = data
+    <<_skip::binary-size(skip), rest::bits>> = data
 
     object_pairs_continue(rest, data, keys, decimal, skip, [
       {object_name(keys, start, name), value} | acc
@@ -256,8 +244,8 @@ defmodule Poison.Parser do
 
   @compile {:inline, array_values: 6}
 
-  defp array_values(<<?], _rest::bits>>, _data, _keys, _decimal, skip, _acc) do
-    [[] | skip + 1]
+  defp array_values(<<?], _rest::bits>>, _data, _keys, _decimal, skip, acc) do
+    [acc | skip + 1]
   end
 
   for char <- whitespace do
@@ -268,7 +256,7 @@ defmodule Poison.Parser do
 
   defp array_values(rest, data, keys, decimal, skip, acc) do
     [value | skip] = value(rest, data, keys, decimal, skip)
-    <<_::binary-size(skip), rest::bits>> = data
+    <<_skip::binary-size(skip), rest::bits>> = data
     array_values_continue(rest, data, keys, decimal, skip, [value | acc])
   end
 
@@ -276,7 +264,7 @@ defmodule Poison.Parser do
 
   defp array_values_continue(<<?,, rest::bits>>, data, keys, decimal, skip, acc) do
     [value | skip] = value(rest, data, keys, decimal, skip + 1)
-    <<_::binary-size(skip), rest::bits>> = data
+    <<_skip::binary-size(skip), rest::bits>> = data
     array_values_continue(rest, data, keys, decimal, skip, [value | acc])
   end
 
@@ -352,7 +340,7 @@ defmodule Poison.Parser do
 
   @compile {:inline, number_exp: 6}
 
-  for e <- 'eE' do
+  for e <- ~c(eE) do
     defp number_exp(<<unquote(e), rest::bits>>, decimal, skip, sign, coef, exp) do
       [value | skip] = number_exp_continue(rest, skip + 1)
       number_complete(decimal, skip, sign, coef, exp + value)
@@ -424,7 +412,7 @@ defmodule Poison.Parser do
 
   # See: https://arxiv.org/pdf/2101.11408.pdf
   defp number_complete(_decimal, skip, sign, coef, exp)
-       when exp in -10..10 and coef <= unquote(max_sig) do
+       when exp in -22..22 and coef <= unquote(max_sig) do
     if exp < 0 do
       [coef / pow10(-exp) * sign | skip]
     else
@@ -440,7 +428,7 @@ defmodule Poison.Parser do
       | skip
     ]
   rescue
-    ArithmeticError ->
+    ArgumentError ->
       reraise ParseError, [skip: skip, value: "#{coef * sign}e#{exp}"], __STACKTRACE__
   end
 
@@ -486,10 +474,13 @@ defmodule Poison.Parser do
         end
 
       unicode ->
-        [
-          :unicode.characters_to_binary([acc | binary_part(data, skip, len)], :utf8)
-          | skip + len + 1
-        ]
+        case :unicode.characters_to_binary([acc | binary_part(data, skip, len)], :utf8) do
+          string when is_binary(string) ->
+            [string | skip + len + 1]
+
+          _other ->
+            syntax_error(skip + len)
+        end
 
       true ->
         [IO.iodata_to_binary([acc | binary_part(data, skip, len)]) | skip + len + 1]
@@ -515,27 +506,21 @@ defmodule Poison.Parser do
 
   @compile {:inline, string_escape: 5}
 
+  defp string_escape(<<?u, rest::bits>>, data, skip, _unicode, acc) do
+    string_escape_unicode(rest, data, skip, acc)
+  end
+
   for {seq, char} <- Enum.zip(~C("\ntr/fb), ~c("\\\n\t\r/\f\b)) do
     defp string_escape(<<unquote(seq), rest::bits>>, data, skip, unicode, acc) do
-      string_continue(rest, data, skip + 1, unicode, 0, [acc | unquote(<<char>>)])
+      string_continue(rest, data, skip + 1, unicode, 0, [acc | [unquote(char)]])
     end
   end
 
-  defp string_escape(
-         <<?u, seq1::binary-size(4), rest::bits>>,
-         data,
-         skip,
-         _unicode,
-         acc
-       ) do
-    string_escape_unicode(rest, data, skip, acc, seq1)
-  end
-
   defp string_escape(_rest, _data, skip, _unicode, _acc), do: syntax_error(skip)
 
-  # http://www.ietf.org/rfc/rfc2781.txt
-  # http://perldoc.perl.org/Encode/Unicode.html#Surrogate-Pairs
-  # http://mathiasbynens.be/notes/javascript-encoding#surrogate-pairs
+  # https://www.ietf.org/rfc/rfc2781.txt
+  # https://perldoc.perl.org/Encode::Unicode#Surrogate-Pairs
+  # https://mathiasbynens.be/notes/javascript-encoding#surrogate-pairs
   defguardp is_hi_surrogate(cp) when cp in 0xD800..0xDBFF
   defguardp is_lo_surrogate(cp) when cp in 0xDC00..0xDFFF
 
@@ -550,18 +535,23 @@ defmodule Poison.Parser do
     end
   end
 
-  @compile {:inline, string_escape_unicode: 5}
+  @compile {:inline, string_escape_unicode: 4}
 
-  defp string_escape_unicode(rest, data, skip, acc, seq1) do
-    cp1 = get_codepoint(seq1, skip)
+  defp string_escape_unicode(<<seq1::binary-size(4), rest::bits>>, data, skip, acc) do
+    case get_codepoint(seq1, skip) do
+      hi when is_hi_surrogate(hi) ->
+        string_escape_surrogate_pair(rest, data, skip, acc, seq1, hi)
 
-    cond do
-      is_hi_surrogate(cp1) -> string_escape_surrogate_pair(rest, data, skip, acc, seq1, cp1)
-      is_lo_surrogate(cp1) -> raise ParseError, skip: skip, value: "\\u#{seq1}"
-      true -> string_continue(rest, data, skip + 5, true, 0, [acc, cp1])
+      lo when is_lo_surrogate(lo) ->
+        raise ParseError, skip: skip, value: "\\u#{seq1}"
+
+      codepoint ->
+        string_continue(rest, data, skip + 5, true, 0, [acc | [codepoint]])
     end
   end
 
+  defp string_escape_unicode(_rest, _data, skip, _acc), do: syntax_error(skip + 1)
+
   @compile {:inline, string_escape_surrogate_pair: 6}
 
   defp string_escape_surrogate_pair(
@@ -572,11 +562,13 @@ defmodule Poison.Parser do
          seq1,
          hi
        ) do
-    with lo when is_lo_surrogate(lo) <- get_codepoint(seq2, skip + 6) do
-      codepoint = 0x10000 + ((hi &&& 0x03FF) <<< 10) + (lo &&& 0x03FF)
-      string_continue(rest, data, skip + 11, true, 0, [acc, codepoint])
-    else
-      _ -> raise ParseError, skip: skip, value: "\\u#{seq1}\\u#{seq2}"
+    case get_codepoint(seq2, skip + 6) do
+      lo when is_lo_surrogate(lo) ->
+        codepoint = 0x10000 + ((hi &&& 0x03FF) <<< 10) + (lo &&& 0x03FF)
+        string_continue(rest, data, skip + 11, true, 0, [acc | [codepoint]])
+
+      _other ->
+        raise ParseError, skip: skip, value: "\\u#{seq1}\\u#{seq2}"
     end
   end
 
diff --git a/mix.exs b/mix.exs
index 8b65ca6..38d1550 100644
--- a/mix.exs
+++ b/mix.exs
@@ -11,7 +11,7 @@ defmodule Poison.Mixfile do
       app: :poison,
       name: "Poison",
       version: @version,
-      elixir: "~> 1.11",
+      elixir: "~> 1.12",
       description: "An incredibly fast, pure Elixir JSON library",
       source_url: "https://github.com/devinus/poison",
       start_permanent: Mix.env() == :prod,
@@ -23,13 +23,13 @@ defmodule Poison.Mixfile do
       aliases: aliases(),
       xref: [exclude: [Decimal]],
       dialyzer: [
-        ignore_warnings: ".dialyzer_ignore.exs",
         plt_add_apps: [:decimal],
         flags: [
           :error_handling,
-          :race_conditions,
-          :underspecs,
-          :unmatched_returns
+          :extra_return,
+          :missing_return,
+          :unmatched_returns,
+          :underspecs
         ]
       ],
       test_coverage: [tool: ExCoveralls],
@@ -46,18 +46,16 @@ defmodule Poison.Mixfile do
   # Run "mix help compile.app" to learn about applications.
   def application do
     # Specify extra applications you'll use from Erlang/Elixir
-    spec = [extra_applications: []]
-
-    if Mix.env() != :bench do
-      spec
+    if Mix.env() == :bench do
+      [extra_applications: [:eex]]
     else
-      Keyword.put_new(spec, :applications, [:logger])
+      []
     end
   end
 
-  defp elixirc_paths() do
+  defp elixirc_paths do
     if Mix.env() == :profile do
-      ["lib", "profile"]
+      ~w(lib profile)
     else
       ["lib"]
     end
@@ -67,19 +65,22 @@ defmodule Poison.Mixfile do
   defp deps do
     [
       {:benchee_html, "~> 1.0", only: :bench, runtime: false},
-      {:benchee, "~> 1.0", only: :bench, runtime: false},
-      {:credo, "~> 1.6", only: [:dev, :test], runtime: false},
-      {:decimal, "~> 2.0", optional: true},
-      {:dialyxir, "~> 1.1", only: [:dev, :test], runtime: false},
-      {:ex_doc, "~> 0.26", only: [:dev, :test], runtime: false},
-      {:excoveralls, "~> 0.14", only: :test, runtime: false},
+      {:benchee_markdown, "~> 0.3", only: :bench, runtime: false},
+      {:benchee, "~> 1.3", only: :bench, runtime: false},
+      {:castore, "~> 1.0", only: :test, runtime: false},
+      {:credo, "~> 1.7.7-rc", only: [:dev, :test], runtime: false},
+      {:decimal, "~> 2.1", optional: true},
+      {:dialyxir, "~> 1.4", only: [:dev, :test], runtime: false},
+      {:ex_doc, "~> 0.34", only: [:dev, :test], runtime: false},
+      {:excoveralls, "~> 0.18", only: :test, runtime: false},
       {:exjsx, "~> 4.0", only: [:bench, :profile], runtime: false},
-      {:jason, "~> 1.2", only: [:dev, :test, :bench, :profile], runtime: false},
-      {:jiffy, "~> 1.0", only: [:bench, :profile], runtime: false},
-      {:json, "~> 1.4", only: [:bench, :profile], runtime: false},
-      {:jsone, "~> 1.7", only: [:bench, :profile], runtime: false},
-      {:junit_formatter, "~> 3.3", only: :test, runtime: false},
-      {:stream_data, "~> 0.5", only: [:dev, :test], runtime: false},
+      {:jason, "~> 1.5.0-alpha", only: [:dev, :test, :bench, :profile], runtime: false},
+      {:jiffy, "~> 1.1", only: [:bench, :profile], runtime: false},
+      {:jsone, "~> 1.8", only: [:bench, :profile], runtime: false},
+      {:junit_formatter, "~> 3.4", only: :test, runtime: false},
+      {:mix_audit, "~> 2.1", only: [:dev, :test], runtime: false},
+      {:stream_data, "~> 1.1", only: [:dev, :test], runtime: false},
+      {:thoas, "~> 1.2", only: [:bench, :profile], runtime: false},
       {:tiny, "~> 1.0", only: [:bench, :profile], runtime: false}
     ]
   end
@@ -88,7 +89,12 @@ defmodule Poison.Mixfile do
     [
       main: "Poison",
       canonical: "https://hexdocs.pm/poison",
-      extras: ["README.md"]
+      extras: [
+        "README.md",
+        "CHANGELOG.md": [title: "Changelog"],
+        LICENSE: [title: "License"]
+      ],
+      source_ref: "master"
     ]
   end
 
@@ -104,8 +110,12 @@ defmodule Poison.Mixfile do
   defp aliases do
     [
       "deps.get": [
-        fn _ ->
-          System.cmd("git", ["submodule", "update", "--init"], cd: __DIR__, parallelism: true)
+        fn _args ->
+          System.cmd("git", ["submodule", "update", "--init"],
+            cd: __DIR__,
+            env: [],
+            parallelism: true
+          )
         end,
         "deps.get"
       ]
diff --git a/mix.lock b/mix.lock
index f01dbfb..11ea273 100644
--- a/mix.lock
+++ b/mix.lock
@@ -1,36 +1,34 @@
 %{
-  "benchee": {:hex, :benchee, "1.0.1", "66b211f9bfd84bd97e6d1beaddf8fc2312aaabe192f776e8931cb0c16f53a521", [:mix], [{:deep_merge, "~> 1.0", [hex: :deep_merge, repo: "hexpm", optional: false]}], "hexpm", "3ad58ae787e9c7c94dd7ceda3b587ec2c64604563e049b2a0e8baafae832addb"},
-  "benchee_html": {:hex, :benchee_html, "1.0.0", "5b4d24effebd060f466fb460ec06576e7b34a00fc26b234fe4f12c4f05c95947", [:mix], [{:benchee, ">= 0.99.0 and < 2.0.0", [hex: :benchee, repo: "hexpm", optional: false]}, {:benchee_json, "~> 1.0", [hex: :benchee_json, repo: "hexpm", optional: false]}], "hexpm", "5280af9aac432ff5ca4216d03e8a93f32209510e925b60e7f27c33796f69e699"},
+  "benchee": {:hex, :benchee, "1.3.1", "c786e6a76321121a44229dde3988fc772bca73ea75170a73fd5f4ddf1af95ccf", [:mix], [{:deep_merge, "~> 1.0", [hex: :deep_merge, repo: "hexpm", optional: false]}, {:statistex, "~> 1.0", [hex: :statistex, repo: "hexpm", optional: false]}, {:table, "~> 0.1.0", [hex: :table, repo: "hexpm", optional: true]}], "hexpm", "76224c58ea1d0391c8309a8ecbfe27d71062878f59bd41a390266bf4ac1cc56d"},
+  "benchee_html": {:hex, :benchee_html, "1.0.1", "1e247c0886c3fdb0d3f4b184b653a8d6fb96e4ad0d0389267fe4f36968772e24", [:mix], [{:benchee, ">= 0.99.0 and < 2.0.0", [hex: :benchee, repo: "hexpm", optional: false]}, {:benchee_json, "~> 1.0", [hex: :benchee_json, repo: "hexpm", optional: false]}], "hexpm", "b00a181af7152431901e08f3fc9f7197ed43ff50421a8347b0c80bf45d5b3fef"},
   "benchee_json": {:hex, :benchee_json, "1.0.0", "cc661f4454d5995c08fe10dd1f2f72f229c8f0fb1c96f6b327a8c8fc96a91fe5", [:mix], [{:benchee, ">= 0.99.0 and < 2.0.0", [hex: :benchee, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "da05d813f9123505f870344d68fb7c86a4f0f9074df7d7b7e2bb011a63ec231c"},
-  "bunt": {:hex, :bunt, "0.2.0", "951c6e801e8b1d2cbe58ebbd3e616a869061ddadcc4863d0a2182541acae9a38", [:mix], [], "hexpm", "7af5c7e09fe1d40f76c8e4f9dd2be7cebd83909f31fee7cd0e9eadc567da8353"},
-  "certifi": {:hex, :certifi, "2.8.0", "d4fb0a6bb20b7c9c3643e22507e42f356ac090a1dcea9ab99e27e0376d695eba", [:rebar3], [], "hexpm", "6ac7efc1c6f8600b08d625292d4bbf584e14847ce1b6b5c44d983d273e1097ea"},
-  "credo": {:hex, :credo, "1.6.1", "7dc76dcdb764a4316c1596804c48eada9fff44bd4b733a91ccbf0c0f368be61e", [:mix], [{:bunt, "~> 0.2.0", [hex: :bunt, repo: "hexpm", optional: false]}, {:file_system, "~> 0.2.8", [hex: :file_system, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "698607fb5993720c7e93d2d8e76f2175bba024de964e160e2f7151ef3ab82ac5"},
-  "decimal": {:hex, :decimal, "2.0.0", "a78296e617b0f5dd4c6caf57c714431347912ffb1d0842e998e9792b5642d697", [:mix], [], "hexpm", "34666e9c55dea81013e77d9d87370fe6cb6291d1ef32f46a1600230b1d44f577"},
+  "benchee_markdown": {:hex, :benchee_markdown, "0.3.3", "d48a1d9782693fae6c294fdb12f653bb90088172d467996bedb9887ff41cf4ef", [:mix], [{:benchee, ">= 1.1.0 and < 2.0.0", [hex: :benchee, repo: "hexpm", optional: false]}], "hexpm", "106dab9ae0b448747da89b9af7285b71841f5d8131f37c6612b7370a157860a4"},
+  "bunt": {:hex, :bunt, "1.0.0", "081c2c665f086849e6d57900292b3a161727ab40431219529f13c4ddcf3e7a44", [:mix], [], "hexpm", "dc5f86aa08a5f6fa6b8096f0735c4e76d54ae5c9fa2c143e5a1fc7c1cd9bb6b5"},
+  "castore": {:hex, :castore, "1.0.7", "b651241514e5f6956028147fe6637f7ac13802537e895a724f90bf3e36ddd1dd", [:mix], [], "hexpm", "da7785a4b0d2a021cd1292a60875a784b6caef71e76bf4917bdee1f390455cf5"},
+  "credo": {:hex, :credo, "1.7.7-rc.0", "a7fb63b6e30e523355fb545cb089c5cba550b6d92e1a70db131e01a5dbb77368", [:mix], [{:bunt, "~> 0.2.1 or ~> 1.0", [hex: :bunt, repo: "hexpm", optional: false]}, {:file_system, "~> 0.2 or ~> 1.0", [hex: :file_system, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "c977f50ada33d6b053122945a0e4e74280585f7f8ac617aca46c913e88cc4de0"},
+  "decimal": {:hex, :decimal, "2.1.1", "5611dca5d4b2c3dd497dec8f68751f1f1a54755e8ed2a966c2633cf885973ad6", [:mix], [], "hexpm", "53cfe5f497ed0e7771ae1a475575603d77425099ba5faef9394932b35020ffcc"},
   "deep_merge": {:hex, :deep_merge, "1.0.0", "b4aa1a0d1acac393bdf38b2291af38cb1d4a52806cf7a4906f718e1feb5ee961", [:mix], [], "hexpm", "ce708e5f094b9cd4e8f2be4f00d2f4250c4095be93f8cd6d018c753894885430"},
-  "dialyxir": {:hex, :dialyxir, "1.1.0", "c5aab0d6e71e5522e77beff7ba9e08f8e02bad90dfbeffae60eaf0cb47e29488", [:mix], [{:erlex, ">= 0.2.6", [hex: :erlex, repo: "hexpm", optional: false]}], "hexpm", "07ea8e49c45f15264ebe6d5b93799d4dd56a44036cf42d0ad9c960bc266c0b9a"},
-  "earmark_parser": {:hex, :earmark_parser, "1.4.17", "6f3c7e94170377ba45241d394389e800fb15adc5de51d0a3cd52ae766aafd63f", [:mix], [], "hexpm", "f93ac89c9feca61c165b264b5837bf82344d13bebc634cd575cb711e2e342023"},
+  "dialyxir": {:hex, :dialyxir, "1.4.3", "edd0124f358f0b9e95bfe53a9fcf806d615d8f838e2202a9f430d59566b6b53b", [:mix], [{:erlex, ">= 0.2.6", [hex: :erlex, repo: "hexpm", optional: false]}], "hexpm", "bf2cfb75cd5c5006bec30141b131663299c661a864ec7fbbc72dfa557487a986"},
+  "earmark_parser": {:hex, :earmark_parser, "1.4.39", "424642f8335b05bb9eb611aa1564c148a8ee35c9c8a8bba6e129d51a3e3c6769", [:mix], [], "hexpm", "06553a88d1f1846da9ef066b87b57c6f605552cfbe40d20bd8d59cc6bde41944"},
   "erlex": {:hex, :erlex, "0.2.6", "c7987d15e899c7a2f34f5420d2a2ea0d659682c06ac607572df55a43753aa12e", [:mix], [], "hexpm", "2ed2e25711feb44d52b17d2780eabf998452f6efda104877a3881c2f8c0c0c75"},
-  "ex_doc": {:hex, :ex_doc, "0.26.0", "1922164bac0b18b02f84d6f69cab1b93bc3e870e2ad18d5dacb50a9e06b542a3", [:mix], [{:earmark_parser, "~> 1.4.0", [hex: :earmark_parser, repo: "hexpm", optional: false]}, {:makeup_elixir, "~> 0.14", [hex: :makeup_elixir, repo: "hexpm", optional: false]}, {:makeup_erlang, "~> 0.1", [hex: :makeup_erlang, repo: "hexpm", optional: false]}], "hexpm", "2775d66e494a9a48355db7867478ffd997864c61c65a47d31c4949459281c78d"},
-  "excoveralls": {:hex, :excoveralls, "0.14.4", "295498f1ae47bdc6dce59af9a585c381e1aefc63298d48172efaaa90c3d251db", [:mix], [{:hackney, "~> 1.16", [hex: :hackney, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "e3ab02f2df4c1c7a519728a6f0a747e71d7d6e846020aae338173619217931c1"},
+  "ex_doc": {:hex, :ex_doc, "0.34.0", "ab95e0775db3df71d30cf8d78728dd9261c355c81382bcd4cefdc74610bef13e", [:mix], [{:earmark_parser, "~> 1.4.39", [hex: :earmark_parser, repo: "hexpm", optional: false]}, {:makeup_c, ">= 0.1.0", [hex: :makeup_c, repo: "hexpm", optional: true]}, {:makeup_elixir, "~> 0.14 or ~> 1.0", [hex: :makeup_elixir, repo: "hexpm", optional: false]}, {:makeup_erlang, "~> 0.1 or ~> 1.0", [hex: :makeup_erlang, repo: "hexpm", optional: false]}, {:makeup_html, ">= 0.1.0", [hex: :makeup_html, repo: "hexpm", optional: true]}], "hexpm", "60734fb4c1353f270c3286df4a0d51e65a2c1d9fba66af3940847cc65a8066d7"},
+  "excoveralls": {:hex, :excoveralls, "0.18.1", "a6f547570c6b24ec13f122a5634833a063aec49218f6fff27de9df693a15588c", [:mix], [{:castore, "~> 1.0", [hex: :castore, repo: "hexpm", optional: true]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "d65f79db146bb20399f23046015974de0079668b9abb2f5aac074d078da60b8d"},
   "exjsx": {:hex, :exjsx, "4.0.0", "60548841e0212df401e38e63c0078ec57b33e7ea49b032c796ccad8cde794b5c", [:mix], [{:jsx, "~> 2.8.0", [hex: :jsx, repo: "hexpm", optional: false]}], "hexpm", "32e95820a97cffea67830e91514a2ad53b888850442d6d395f53a1ac60c82e07"},
-  "file_system": {:hex, :file_system, "0.2.10", "fb082005a9cd1711c05b5248710f8826b02d7d1784e7c3451f9c1231d4fc162d", [:mix], [], "hexpm", "41195edbfb562a593726eda3b3e8b103a309b733ad25f3d642ba49696bf715dc"},
-  "hackney": {:hex, :hackney, "1.18.0", "c4443d960bb9fba6d01161d01cd81173089686717d9490e5d3606644c48d121f", [:rebar3], [{:certifi, "~>2.8.0", [hex: :certifi, repo: "hexpm", optional: false]}, {:idna, "~>6.1.0", [hex: :idna, repo: "hexpm", optional: false]}, {:metrics, "~>1.0.0", [hex: :metrics, repo: "hexpm", optional: false]}, {:mimerl, "~>1.1", [hex: :mimerl, repo: "hexpm", optional: false]}, {:parse_trans, "3.3.1", [hex: :parse_trans, repo: "hexpm", optional: false]}, {:ssl_verify_fun, "~>1.1.0", [hex: :ssl_verify_fun, repo: "hexpm", optional: false]}, {:unicode_util_compat, "~>0.7.0", [hex: :unicode_util_compat, repo: "hexpm", optional: false]}], "hexpm", "9afcda620704d720db8c6a3123e9848d09c87586dc1c10479c42627b905b5c5e"},
-  "idna": {:hex, :idna, "6.1.1", "8a63070e9f7d0c62eb9d9fcb360a7de382448200fbbd1b106cc96d3d8099df8d", [:rebar3], [{:unicode_util_compat, "~>0.7.0", [hex: :unicode_util_compat, repo: "hexpm", optional: false]}], "hexpm", "92376eb7894412ed19ac475e4a86f7b413c1b9fbb5bd16dccd57934157944cea"},
-  "jason": {:hex, :jason, "1.2.2", "ba43e3f2709fd1aa1dce90aaabfd039d000469c05c56f0b8e31978e03fa39052", [:mix], [{:decimal, "~> 1.0 or ~> 2.0", [hex: :decimal, repo: "hexpm", optional: true]}], "hexpm", "18a228f5f0058ee183f29f9eae0805c6e59d61c3b006760668d8d18ff0d12179"},
-  "jiffy": {:hex, :jiffy, "1.0.8", "60e36f00be35e5ac6e6cf2d4caf3bdf3103d4460aff385f543a8d7df2d6d9613", [:rebar3], [], "hexpm", "f9ae986ba5a0854eb48cf6a76192d9367086da86c20197da430630be7c087a4e"},
-  "json": {:hex, :json, "1.4.1", "8648f04a9439765ad449bc56a3ff7d8b11dd44ff08ffcdefc4329f7c93843dfa", [:mix], [], "hexpm", "9abf218dbe4ea4fcb875e087d5f904ef263d012ee5ed21d46e9dbca63f053d16"},
-  "jsone": {:hex, :jsone, "1.7.0", "1e3bd7d5dd44bb2eb0797dddea1cbf2ddab8d9f29e499a467ca171c23f5984ea", [:rebar3], [], "hexpm", "a3a33712ee6bc8be10cfa21c7c425a299de4c5a8533f9f931e577a6d0e8f5dbd"},
+  "file_system": {:hex, :file_system, "1.0.0", "b689cc7dcee665f774de94b5a832e578bd7963c8e637ef940cd44327db7de2cd", [:mix], [], "hexpm", "6752092d66aec5a10e662aefeed8ddb9531d79db0bc145bb8c40325ca1d8536d"},
+  "jason": {:hex, :jason, "1.5.0-alpha.2", "42bc9c545bcdf2d5096044449ddcf85235cdbfbaa19792f4a8be581c8f72608e", [:mix], [{:decimal, "~> 1.0 or ~> 2.0", [hex: :decimal, repo: "hexpm", optional: true]}, {:jason_native, ">= 0.0.0", [hex: :jason_native, repo: "hexpm", optional: true]}], "hexpm", "6dcaa0d9fdc22afe9b4d362f17f20844a85f121c50b6e9b9466ac04fe39f3665"},
+  "jiffy": {:hex, :jiffy, "1.1.1", "aca10f47aa91697bf24ab9582c74e00e8e95474c7ef9f76d4f1a338d0f5de21b", [:rebar3], [], "hexpm", "62e1f0581c3c19c33a725c781dfa88410d8bff1bbafc3885a2552286b4785c4c"},
+  "jsone": {:hex, :jsone, "1.8.1", "6bc74d3863d55d420077346da97c601711017a057f2fd1df65d6d65dd562fbab", [:rebar3], [], "hexpm", "c78918124148c51a7a84c678e39bbc6281f8cb582f1d88584628a98468e99738"},
   "jsx": {:hex, :jsx, "2.8.3", "a05252d381885240744d955fbe3cf810504eb2567164824e19303ea59eef62cf", [:mix, :rebar3], [], "hexpm", "fc3499fed7a726995aa659143a248534adc754ebd16ccd437cd93b649a95091f"},
-  "junit_formatter": {:hex, :junit_formatter, "3.3.0", "bd7914d92885f7cf949dbe1dc6bacf76badfb2c1f5f7b3f9433c20e5b6ec42c8", [:mix], [], "hexpm", "4d040410925324b155ae4c7d41e884a0cdebe53b917bee4f22adf152e987a666"},
-  "makeup": {:hex, :makeup, "1.0.5", "d5a830bc42c9800ce07dd97fa94669dfb93d3bf5fcf6ea7a0c67b2e0e4a7f26c", [:mix], [{:nimble_parsec, "~> 0.5 or ~> 1.0", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "cfa158c02d3f5c0c665d0af11512fed3fba0144cf1aadee0f2ce17747fba2ca9"},
-  "makeup_elixir": {:hex, :makeup_elixir, "0.15.2", "dc72dfe17eb240552857465cc00cce390960d9a0c055c4ccd38b70629227e97c", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}, {:nimble_parsec, "~> 1.1", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "fd23ae48d09b32eff49d4ced2b43c9f086d402ee4fd4fcb2d7fad97fa8823e75"},
-  "makeup_erlang": {:hex, :makeup_erlang, "0.1.1", "3fcb7f09eb9d98dc4d208f49cc955a34218fc41ff6b84df7c75b3e6e533cc65f", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}], "hexpm", "174d0809e98a4ef0b3309256cbf97101c6ec01c4ab0b23e926a9e17df2077cbb"},
-  "metrics": {:hex, :metrics, "1.0.1", "25f094dea2cda98213cecc3aeff09e940299d950904393b2a29d191c346a8486", [:rebar3], [], "hexpm", "69b09adddc4f74a40716ae54d140f93beb0fb8978d8636eaded0c31b6f099f16"},
-  "mimerl": {:hex, :mimerl, "1.2.0", "67e2d3f571088d5cfd3e550c383094b47159f3eee8ffa08e64106cdf5e981be3", [:rebar3], [], "hexpm", "f278585650aa581986264638ebf698f8bb19df297f66ad91b18910dfc6e19323"},
-  "nimble_parsec": {:hex, :nimble_parsec, "1.2.0", "b44d75e2a6542dcb6acf5d71c32c74ca88960421b6874777f79153bbbbd7dccc", [:mix], [], "hexpm", "52b2871a7515a5ac49b00f214e4165a40724cf99798d8e4a65e4fd64ebd002c1"},
-  "parse_trans": {:hex, :parse_trans, "3.3.1", "16328ab840cc09919bd10dab29e431da3af9e9e7e7e6f0089dd5a2d2820011d8", [:rebar3], [], "hexpm", "07cd9577885f56362d414e8c4c4e6bdf10d43a8767abb92d24cbe8b24c54888b"},
-  "ssl_verify_fun": {:hex, :ssl_verify_fun, "1.1.6", "cf344f5692c82d2cd7554f5ec8fd961548d4fd09e7d22f5b62482e5aeaebd4b0", [:make, :mix, :rebar3], [], "hexpm", "bdb0d2471f453c88ff3908e7686f86f9be327d065cc1ec16fa4540197ea04680"},
-  "stream_data": {:hex, :stream_data, "0.5.0", "b27641e58941685c75b353577dc602c9d2c12292dd84babf506c2033cd97893e", [:mix], [], "hexpm", "012bd2eec069ada4db3411f9115ccafa38540a3c78c4c0349f151fc761b9e271"},
+  "junit_formatter": {:hex, :junit_formatter, "3.4.0", "d0e8db6c34dab6d3c4154c3b46b21540db1109ae709d6cf99ba7e7a2ce4b1ac2", [:mix], [], "hexpm", "bb36e2ae83f1ced6ab931c4ce51dd3dbef1ef61bb4932412e173b0cfa259dacd"},
+  "makeup": {:hex, :makeup, "1.1.2", "9ba8837913bdf757787e71c1581c21f9d2455f4dd04cfca785c70bbfff1a76a3", [:mix], [{:nimble_parsec, "~> 1.2.2 or ~> 1.3", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "cce1566b81fbcbd21eca8ffe808f33b221f9eee2cbc7a1706fc3da9ff18e6cac"},
+  "makeup_elixir": {:hex, :makeup_elixir, "0.16.2", "627e84b8e8bf22e60a2579dad15067c755531fea049ae26ef1020cad58fe9578", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}, {:nimble_parsec, "~> 1.2.3 or ~> 1.3", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "41193978704763f6bbe6cc2758b84909e62984c7752b3784bd3c218bb341706b"},
+  "makeup_erlang": {:hex, :makeup_erlang, "1.0.0", "6f0eff9c9c489f26b69b61440bf1b238d95badae49adac77973cbacae87e3c2e", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}], "hexpm", "ea7a9307de9d1548d2a72d299058d1fd2339e3d398560a0e46c27dab4891e4d2"},
+  "mix_audit": {:hex, :mix_audit, "2.1.3", "c70983d5cab5dca923f9a6efe559abfb4ec3f8e87762f02bab00fa4106d17eda", [:make, :mix], [{:jason, "~> 1.1", [hex: :jason, repo: "hexpm", optional: false]}, {:yaml_elixir, "~> 2.9", [hex: :yaml_elixir, repo: "hexpm", optional: false]}], "hexpm", "8c3987100b23099aea2f2df0af4d296701efd031affb08d0746b2be9e35988ec"},
+  "nimble_parsec": {:hex, :nimble_parsec, "1.4.0", "51f9b613ea62cfa97b25ccc2c1b4216e81df970acd8e16e8d1bdc58fef21370d", [:mix], [], "hexpm", "9c565862810fb383e9838c1dd2d7d2c437b3d13b267414ba6af33e50d2d1cf28"},
+  "statistex": {:hex, :statistex, "1.0.0", "f3dc93f3c0c6c92e5f291704cf62b99b553253d7969e9a5fa713e5481cd858a5", [:mix], [], "hexpm", "ff9d8bee7035028ab4742ff52fc80a2aa35cece833cf5319009b52f1b5a86c27"},
+  "stream_data": {:hex, :stream_data, "1.1.0", "ef3a7cac0f200c43caf3e6caf9be63115851b4f1cde3f21afaab220adc40e3d7", [:mix], [], "hexpm", "cccc411d5facf1bab86e7c671382d164f05f8992574c95349d3c8b317e14d953"},
+  "thoas": {:hex, :thoas, "1.2.1", "19a25f31177a17e74004d4840f66d791d4298c5738790fa2cc73731eb911f195", [:rebar3], [], "hexpm", "e38697edffd6e91bd12cea41b155115282630075c2a727e7a6b2947f5408b86a"},
   "tiny": {:hex, :tiny, "1.0.1", "535ea7e600cb1c6ba17b53029266d9d7ec54ce29bfb05d906c433907acfa01ca", [:mix], [], "hexpm", "1278a457deb8d99135c378b71f66f21e283d8adea426252a3f8f5e003c536a7b"},
-  "unicode_util_compat": {:hex, :unicode_util_compat, "0.7.0", "bc84380c9ab48177092f43ac89e4dfa2c6d62b40b8bd132b1059ecc7232f9a78", [:rebar3], [], "hexpm", "25eee6d67df61960cf6a794239566599b09e17e668d3700247bc498638152521"},
+  "yamerl": {:hex, :yamerl, "0.10.0", "4ff81fee2f1f6a46f1700c0d880b24d193ddb74bd14ef42cb0bcf46e81ef2f8e", [:rebar3], [], "hexpm", "346adb2963f1051dc837a2364e4acf6eb7d80097c0f53cbdc3046ec8ec4b4e6e"},
+  "yaml_elixir": {:hex, :yaml_elixir, "2.9.0", "9a256da867b37b8d2c1ffd5d9de373a4fda77a32a45b452f1708508ba7bbcb53", [:mix], [{:yamerl, "~> 0.10", [hex: :yamerl, repo: "hexpm", optional: false]}], "hexpm", "0cb0e7d4c56f5e99a6253ed1a670ed0e39c13fc45a6da054033928607ac08dfc"},
 }
diff --git a/profile/profiler.ex b/profile/profiler.ex
index 2410979..42a0a08 100644
--- a/profile/profiler.ex
+++ b/profile/profiler.ex
@@ -11,6 +11,7 @@ defmodule Poison.Profiler do
         path
         |> Path.basename(".json")
         |> String.replace(~r/-+/, "_")
+        # credo:disable-for-next-line Credo.Check.Warning.UnsafeToAtom
         |> String.to_atom()
 
       value = File.read!(path)
diff --git a/test/poison/encoder_test.exs b/test/poison/encoder_test.exs
index e136dbb..7477431 100644
--- a/test/poison/encoder_test.exs
+++ b/test/poison/encoder_test.exs
@@ -4,13 +4,14 @@ defmodule Poison.EncoderTest do
 
   import Poison.TestGenerators
 
+  import Poison, only: [encode!: 1, encode!: 2]
   alias Poison.{EncodeError, Encoder}
 
   test "Atom" do
-    assert to_json(nil) == "null"
-    assert to_json(true) == "true"
-    assert to_json(false) == "false"
-    assert to_json(:poison) == ~s("poison")
+    assert encode!(nil) == "null"
+    assert encode!(true) == "true"
+    assert encode!(false) == "false"
+    assert encode!(:poison) == ~s("poison")
   end
 
   property "Atom" do
@@ -19,57 +20,62 @@ defmodule Poison.EncoderTest do
             # credo:disable-for-next-line Credo.Check.Warning.UnsafeToAtom
             value = String.to_atom(str)
           ) do
-      assert to_json(value) == inspect(str)
+      assert encode!(value) == inspect(str)
     end
   end
 
   test "Integer" do
-    assert to_json(42) == "42"
+    assert encode!(42) == "42"
+    assert encode!(576_460_752_303_423_488) == "576460752303423488"
   end
 
   property "Integer" do
     check all(value <- integer()) do
-      assert to_json(value) == to_string(value)
+      assert encode!(value) == to_string(value)
     end
   end
 
   test "Float" do
-    assert to_json(99.99) == "99.99"
-    assert to_json(9.9e100) == "9.9e100"
+    assert encode!(99.99) == "99.99"
+    assert encode!(9.9e100) == "9.9e100"
+    assert encode!(9.9e-100) == "9.9e-100"
   end
 
   property "Float" do
     check all(value <- float()) do
-      assert to_json(value) == to_string(value)
+      assert encode!(value) == to_string(value)
     end
   end
 
   test "BitString" do
-    assert to_json("hello world") == ~s("hello world")
-    assert to_json("hello\nworld") == ~s("hello\\nworld")
-    assert to_json("\nhello\nworld\n") == ~s("\\nhello\\nworld\\n")
-
-    assert to_json("\"") == ~s("\\"")
-    assert to_json("\0") == ~s("\\u0000")
-    assert to_json(<<31>>) == ~s("\\u001F")
-    assert to_json("☃", escape: :unicode) == ~s("\\u2603")
-    assert to_json("𝄞", escape: :unicode) == ~s("\\uD834\\uDD1E")
-    assert to_json("\u2028\u2029", escape: :javascript) == ~s("\\u2028\\u2029")
-    assert to_json("</script>", escape: :html_safe) == ~s("<\\/script>")
-
-    assert to_json("\uCCCC</script>\uCCCC", escape: :html_safe) ==
-             ~s("쳌<\\/script>쳌")
-
-    assert to_json(~s(<script>var s = "\u2028\u2029";</script>),
-             escape: :html_safe
-           ) == ~s("<script>var s = \\\"\\u2028\\u2029\\\";<\\/script>")
-
-    assert to_json("áéíóúàèìòùâêîôûãẽĩõũ") == ~s("áéíóúàèìòùâêîôûãẽĩõũ")
+    assert encode!("") == ~s("")
+    assert encode!("hello world") == ~s("hello world")
+    assert encode!("hello\nworld") == ~s("hello\\nworld")
+    assert encode!("\nhello\nworld\n") == ~s("\\nhello\\nworld\\n")
+
+    assert encode!("\"") == ~s("\\"")
+    assert encode!("\0") == ~s("\\u0000")
+    assert encode!(<<31>>) == ~s("\\u001F")
+    assert encode!("☃", escape: :unicode) == ~s("\\u2603")
+    assert encode!("𝄞", escape: :unicode) == ~s("\\uD834\\uDD1E")
+    assert encode!("\u2028\u2029", escape: :javascript) == ~s("\\u2028\\u2029")
+    assert encode!("</script>", escape: :html_safe) == ~s("\\u003C/script\\u003E")
+
+    assert encode!("\uCCCC</script>\uCCCC", escape: :html_safe) ==
+             ~s("쳌\\u003C/script\\u003E쳌")
+
+    assert encode!(~s(<script>var s = "\u2028\u2029";</script>), escape: :html_safe) ==
+             ~s("\\u003Cscript\\u003Evar s = \\\"\\u2028\\u2029\\\";\\u003C/script\\u003E")
+
+    assert encode!("<!-- comment -->", escape: :html_safe) == ~s("\\u003C!-- comment --\\u003E")
+    assert encode!("one & two", escape: :html_safe) == ~s("one \\u0026 two")
+
+    assert encode!("áéíóúàèìòùâêîôûãẽĩõũ") == ~s("áéíóúàèìòùâêîôûãẽĩõũ")
   end
 
   property "BitString" do
-    check all(value <- json_string()) do
-      assert to_json(value) == inspect(value)
+    check all(value <- json_string(min_length: 1)) do
+      assert encode!(value) == inspect(value)
     end
 
     check all(
@@ -78,7 +84,7 @@ defmodule Poison.EncoderTest do
             <<codepoint::utf8>> = elem
           ) do
       seq = codepoint |> Integer.to_string(16) |> String.pad_leading(4, "0")
-      assert to_json(<<codepoint::utf8>>, escape: :unicode) == ~s("\\u#{seq}")
+      assert encode!(<<codepoint::utf8>>, escape: :unicode) == ~s("\\u#{seq}")
     end
 
     check all(
@@ -89,111 +95,73 @@ defmodule Poison.EncoderTest do
       seq2 = lo |> Integer.to_string(16) |> String.pad_leading(4, "0")
       <<codepoint::utf16>> = <<hi::16, lo::16>>
       value = :unicode.characters_to_binary([codepoint], :utf16, :utf8)
-      assert to_json(value, escape: :unicode) == ~s("\\u#{seq1}\\u#{seq2}")
+      assert encode!(value, escape: :unicode) == ~s("\\u#{seq1}\\u#{seq2}")
     end
   end
 
   property "List" do
     check all(value <- json_list(min_length: 1)) do
-      assert String.match?(to_json(value), ~r/^\[.*\]$/)
+      assert String.match?(encode!(value), ~r/^\[(([^,]+,)|[^\]]+){1,#{length(value)}}\]$/)
     end
   end
 
   test "Map" do
-    assert to_json(%{}) == "{}"
-    assert to_json(%{"foo" => "bar"}) == ~s({"foo":"bar"})
-    assert to_json(%{foo: :bar}) == ~s({"foo":"bar"})
-    assert to_json(%{42 => :bar}) == ~s({"42":"bar"})
-
-    assert to_json(%{foo: %{bar: %{baz: "baz"}}}, pretty: true) == """
-           {
-             "foo": {
-               "bar": {
-                 "baz": "baz"
-               }
-             }
-           }\
-           """
+    assert encode!(%{}) == "{}"
+    assert encode!(%{"foo" => "bar"}) == ~s({"foo":"bar"})
+    assert encode!(%{foo: :bar}) == ~s({"foo":"bar"})
+    assert encode!(%{42 => :bar}) == ~s({"42":"bar"})
+
+    assert encode!(%{foo: %{bar: %{baz: "baz"}}}, pretty: true) ==
+             "{\n  \"foo\": {\n    \"bar\": {\n      \"baz\": \"baz\"\n    }\n  }\n}"
 
     multi_key_map = %{"foo" => "foo1", :foo => "foo2"}
-    assert to_json(multi_key_map) == ~s({"foo":"foo1","foo":"foo2"})
+    assert encode!(multi_key_map) == ~s({"foo":"foo1","foo":"foo2"})
     error = %EncodeError{message: "duplicate key found: :foo", value: "foo"}
     assert Poison.encode(multi_key_map, strict_keys: true) == {:error, error}
   end
 
   property "Map" do
     check all(value <- json_map(min_length: 1)) do
-      assert String.match?(to_json(value), ~r/^{.*}$/)
+      assert String.match?(encode!(value), ~r/^\{([^:]+:[^,]+){1,#{map_size(value)}}\}$/)
     end
   end
 
   test "Range" do
-    assert to_json(1..3) == "[1,2,3]"
-
-    assert to_json(1..3, pretty: true) == """
-           [
-             1,
-             2,
-             3
-           ]\
-           """
+    assert encode!(1..3) == "[1,2,3]"
+    assert encode!(1..3, pretty: true) == "[\n  1,\n  2,\n  3\n]"
   end
 
   test "Stream" do
     range = 1..10
-    assert to_json(Stream.take(range, 0)) == "[]"
-    assert to_json(Stream.take(range, 3)) == "[1,2,3]"
-
-    assert to_json(Stream.take(range, 3), pretty: true) == """
-           [
-             1,
-             2,
-             3
-           ]\
-           """
+    assert encode!(Stream.take(range, 0)) == "[]"
+    assert encode!(Stream.take(range, 3)) == "[1,2,3]"
+    assert encode!(Stream.take(range, 3), pretty: true) == "[\n  1,\n  2,\n  3\n]"
   end
 
-  # MapSet/HashSet have an unspecified order
-
-  test "MapSet/HashSet" do
-    for type <- [MapSet, HashSet] do
-      set = type.new
-      assert to_json(set) == "[]"
-
-      set = set |> type.put(1) |> type.put(2)
-
-      assert to_json(set) in ~w([1,2] [2,1])
-
-      assert to_json(set, pretty: true) in [
-               """
-               [
-                 1,
-                 2
-               ]\
-               """,
-               """
-               [
-                 2,
-                 1
-               ]\
-               """
-             ]
-    end
+  # MapSet have an unspecified order
+
+  test "MapSet" do
+    set = MapSet.new()
+    assert encode!(set) == "[]"
+
+    set = set |> MapSet.put(1) |> MapSet.put(2)
+    assert encode!(set) in ~w([1,2] [2,1])
+    assert encode!(set, pretty: true) in ["[\n  1,\n  2\n]", "[\n  2,\n  1\n]"]
   end
 
   test "Time" do
     {:ok, time} = Time.new(12, 13, 14)
-    assert to_json(time) == ~s("12:13:14")
+    assert encode!(time) == ~s("12:13:14")
   end
 
   test "Date" do
     {:ok, date} = Date.new(2000, 1, 1)
-    assert to_json(date) == ~s("2000-01-01")
+    assert encode!(date) == ~s("2000-01-01")
   end
 
   test "NaiveDateTime" do
     {:ok, datetime} = NaiveDateTime.new(2000, 1, 1, 12, 13, 14)
-    assert to_json(datetime) == ~s("2000-01-01T12:13:14")
+    assert encode!(datetime) == ~s("2000-01-01T12:13:14")
   end
 
   test "DateTime" do
@@ -211,7 +179,7 @@ defmodule Poison.EncoderTest do
       utc_offset: 3600
     }
 
-    assert to_json(datetime) == ~s("2000-01-01T12:13:14+00:30")
+    assert encode!(datetime) == ~s("2000-01-01T12:13:14+00:30")
 
     datetime = %DateTime{
       year: 2000,
@@ -227,22 +195,27 @@ defmodule Poison.EncoderTest do
       utc_offset: 0
     }
 
-    assert to_json(datetime) == ~s("2000-01-01T12:13:14.050Z")
+    assert encode!(datetime) == ~s("2000-01-01T12:13:14.050Z")
+  end
+
+  test "Date.Range" do
+    assert encode!(Date.range(~D[1969-08-15], ~D[1969-08-18])) ==
+             ~s(["1969-08-15","1969-08-16","1969-08-17","1969-08-18"])
   end
 
   test "URI" do
     uri = URI.parse("https://devinus.io")
-    assert to_json(uri) == ~s("https://devinus.io")
+    assert encode!(uri) == ~s("https://devinus.io")
   end
 
   test "Decimal" do
     decimal = Decimal.new("99.9")
-    assert to_json(decimal) == "99.9"
+    assert encode!(decimal) == "99.9"
   end
 
   property "Decimal" do
     check all(value <- map(float(), &Decimal.from_float/1)) do
-      assert to_json(value) == to_string(value)
+      assert encode!(value) == to_string(value)
     end
   end
 
@@ -276,7 +249,7 @@ defmodule Poison.EncoderTest do
       size: 10
     }
 
-    assert Poison.decode!(to_json(derived_using_only)) == %{
+    assert Poison.decode!(encode!(derived_using_only)) == %{
              "name" => "derived using :only"
            }
 
@@ -285,12 +258,12 @@ defmodule Poison.EncoderTest do
       size: 10
     }
 
-    assert Poison.decode!(to_json(derived_using_except)) == %{"size" => 10}
+    assert Poison.decode!(encode!(derived_using_except)) == %{"size" => 10}
   end
 
   test "EncodeError" do
     assert_raise EncodeError, fn ->
-      to_json(self())
+      encode!(make_ref())
     end
   end
 
@@ -305,13 +278,7 @@ defmodule Poison.EncoderTest do
                 offset: positive_integer()
               })
           ) do
-      assert to_json(value, options) != ""
+      assert encode!(value, options) != ""
     end
   end
-
-  defp to_json(value, options \\ []) do
-    value
-    |> Encoder.encode(Map.new(options))
-    |> IO.iodata_to_binary()
-  end
 end
diff --git a/test/poison/parser_test.exs b/test/poison/parser_test.exs
index 8872b07..6acba41 100644
--- a/test/poison/parser_test.exs
+++ b/test/poison/parser_test.exs
@@ -34,25 +34,25 @@ defmodule Poison.ParserTest do
       parse!("1.0e+")
     end
 
-    assert parse!("0") == 0
-    assert parse!("1") == 1
-    assert parse!("-0") == 0
-    assert parse!("-1") == -1
-    assert parse!("0.1") == 0.1
-    assert parse!("-0.1") == -0.1
-    assert parse!("0e0") == 0
-    assert parse!("0E0") == 0
-    assert parse!("1e0") == 1
-    assert parse!("1E0") == 1
-    assert parse!("1.0e0") == 1.0
-    assert parse!("1e+0") == 1
-    assert parse!("1.0e+0") == 1.0
-    assert parse!("0.1e1") == 0.1e1
-    assert parse!("0.1e-1") == 0.1e-1
-    assert parse!("99.99e99") == 99.99e99
+    assert parse!("0") === 0
+    assert parse!("1") === 1
+    assert parse!("-0") === 0
+    assert parse!("-1") === -1
+    assert parse!("0.1") === 0.1
+    assert parse!("-0.1") === -0.1
+    assert parse!("0e0") === 0
+    assert parse!("0E0") === 0
+    assert parse!("1e0") === 1
+    assert parse!("1E0") === 1
+    assert parse!("1.0e0") === 1.0
+    assert parse!("1e+0") === 1
+    assert parse!("1.0e+0") === 1.0
+    assert parse!("0.1e1") === 1
+    assert parse!("0.1e-1") === 0.1e-1
+    assert parse!("99.99e99") === 99.99e99
 
     # credo:disable-for-next-line Credo.Check.Readability.LargeNumbers
-    assert parse!("123456789.123456789e123") == 1.234567891234568e131
+    assert parse!("123456789.123456789e123") === 1.234567891234568e131
 
     assert parse!("0", %{decimal: true}) == Decimal.new("0")
     assert parse!("-0", %{decimal: true}) == Decimal.new("-0")
@@ -69,7 +69,7 @@ defmodule Poison.ParserTest do
 
   property "number" do
     check all(int <- integer()) do
-      assert parse!(Integer.to_string(int)) == int
+      assert parse!(Integer.to_string(int)) === int
     end
 
     check all(value <- float()) do
@@ -244,12 +244,12 @@ defmodule Poison.ParserTest do
   end
 
   test "atom keys" do
-    hash = :erlang.phash2(:crypto.strong_rand_bytes(8))
+    uint = :erlang.unique_integer([:positive])
 
     assert_raise ParseError,
-                 ~s(cannot parse value at position 2: "key#{hash}"),
+                 ~s(cannot parse value at position 2: "key#{uint}"),
                  fn ->
-                   parse!(~s({"key#{hash}": null}), %{keys: :atoms!})
+                   parse!(~s({"key#{uint}": null}), %{keys: :atoms!})
                  end
 
     assert parse!(~s({"foo": "bar"}), %{keys: :atoms!}) == %{foo: "bar"}
diff --git a/test/test_helper.exs b/test/test_helper.exs
index bab4c54..a8c42ad 100644
--- a/test/test_helper.exs
+++ b/test/test_helper.exs
@@ -23,22 +23,17 @@ defmodule Poison.TestGenerators do
   end
 
   def json_map(options \\ []) do
-    map_of(json_string(), json_value(), options)
+    map_of(json_string(min_length: 1), json_value(), options)
   end
 
   def json_complex_value do
-    one_of([
+    tree(
       json_value(),
-      json_list(),
-      map_of(
-        json_string(),
-        one_of([
-          json_value(),
-          json_list(),
-          json_map()
-        ])
-      )
-    ])
+      &one_of([
+        list_of(&1),
+        map_of(json_string(min_length: 1), &1)
+      ])
+    )
   end
 end
 
diff --git a/vendor/JSONTestSuite b/vendor/JSONTestSuite
index d64aefb..984defc 160000
--- a/vendor/JSONTestSuite
+++ b/vendor/JSONTestSuite
@@ -1 +1 @@
-Subproject commit d64aefb55228d9584d3e5b2433f720ea8fd00c82
+Subproject commit 984defc2deaa653cb73cd29f4144a720ec9efe7c