diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 000000000..6d1b1649a
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "haskell/worker/impl"]
+	path = haskell/worker/impl
+	url = git@github.com:MercuryTechnologies/ghc-persistent-worker
diff --git a/decls/haskell_common.bzl b/decls/haskell_common.bzl
index 0f704f71d..670a2057e 100644
--- a/decls/haskell_common.bzl
+++ b/decls/haskell_common.bzl
@@ -53,6 +53,7 @@ def _scripts_arg():
             providers = [RunInfo],
             default = "prelude//haskell/tools:ghc_wrapper",
         ),
+        "_worker": attrs.option(attrs.exec_dep(providers = [WorkerInfo]), default = None),
     }
 
 def _external_tools_arg():
diff --git a/decls/haskell_rules.bzl b/decls/haskell_rules.bzl
index 61d2107ca..c3d9a75eb 100644
--- a/decls/haskell_rules.bzl
+++ b/decls/haskell_rules.bzl
@@ -14,6 +14,7 @@ load("@prelude//linking:types.bzl", "Linkage")
 load(":common.bzl", "LinkableDepType", "buck", "prelude_rule")
 load(":haskell_common.bzl", "haskell_common")
 load(":native_common.bzl", "native_common")
+load("@prelude//haskell/worker/worker.bzl", "worker_libs", "worker_srcs", "worker_flags")
 
 haskell_binary = prelude_rule(
     name = "haskell_binary",
@@ -66,6 +67,9 @@ haskell_binary = prelude_rule(
             "linker_flags": attrs.list(attrs.arg(), default = []),
             "platform": attrs.option(attrs.string(), default = None),
             "platform_linker_flags": attrs.list(attrs.tuple(attrs.regex(), attrs.list(attrs.arg())), default = []),
+            "_worker_srcs": attrs.list(attrs.source(), default = worker_srcs),
+            "_worker_deps": attrs.list(attrs.dep(), default = ["@prelude//haskell/worker:{}".format(pkg) for pkg in worker_libs]),
+            "_worker_compiler_flags": attrs.list(attrs.string(), default = worker_flags),
         }
     ),
 )
@@ -188,6 +192,9 @@ haskell_library = prelude_rule(
             "linker_flags": attrs.list(attrs.arg(), default = []),
             "platform": attrs.option(attrs.string(), default = None),
             "platform_linker_flags": attrs.list(attrs.tuple(attrs.regex(), attrs.list(attrs.arg())), default = []),
+            "_worker_srcs": attrs.list(attrs.source(), default = worker_srcs),
+            "_worker_deps": attrs.list(attrs.dep(), default = ["@prelude//haskell/worker:{}".format(pkg) for pkg in worker_libs]),
+            "_worker_compiler_flags": attrs.list(attrs.string(), default = worker_flags),
         }
     ),
 )
diff --git a/haskell/compile.bzl b/haskell/compile.bzl
index 35893225a..9ec3655f3 100644
--- a/haskell/compile.bzl
+++ b/haskell/compile.bzl
@@ -441,6 +441,7 @@ def _common_compile_module_args(
 ) -> CommonCompileModuleArgs:
     command = cmd_args(ghc_wrapper)
     command.add("--ghc", haskell_toolchain.compiler)
+    command.add("--ghc-dir", haskell_toolchain.ghc_dir)
 
     # Some rules pass in RTS (e.g. `+RTS ... -RTS`) options for GHC, which can't
     # be parsed when inside an argsfile.
@@ -579,6 +580,7 @@ def _compile_module(
     aux_deps: None | list[Artifact],
     src_envs: None | dict[str, ArgLike],
     source_prefixes: list[str],
+    worker: None | WorkerInfo,
 ) -> CompiledModuleTSet:
     # These compiler arguments can be passed in a response file.
     compile_args_for_file = cmd_args(common_args.args_for_file, hidden = aux_deps or [])
@@ -699,6 +701,7 @@ def _compile_module(
     compile_cmd.add("-fwrite-if-simplified-core")
     if enable_th:
         compile_cmd.add("-fprefer-byte-code")
+        compile_cmd.add("-fpackage-db-byte-code")
 
     compile_cmd.add(cmd_args(dependency_modules.reduce("packagedb_deps").keys(), prepend = "--buck2-package-db"))
 
@@ -709,6 +712,8 @@ def _compile_module(
     compile_cmd.add("--buck2-dep", tagged_dep_file)
     compile_cmd.add("--abi-out", outputs[module.hash])
 
+    worker_args = dict() if worker == None else dict(exe = WorkerRunInfo(worker = worker))
+
     actions.run(
         compile_cmd, category = "haskell_compile_" + artifact_suffix.replace("-", "_"), identifier = module_name,
         dep_files = {
@@ -717,6 +722,7 @@ def _compile_module(
         },
         # explicit turn this on for local_only actions to upload their results.
         allow_cache_upload = True,
+        **worker_args,
     )
 
     module_tset = actions.tset(
@@ -783,6 +789,7 @@ def _dynamic_do_compile_impl(actions, md_file, pkg_deps, arg, direct_deps_by_nam
             direct_deps_by_name = direct_deps_by_name,
             toolchain_deps_by_name = arg.toolchain_deps_by_name,
             source_prefixes = source_prefixes,
+            worker = arg.worker,
         )
 
     return [DynamicCompileResultInfo(modules = module_tsets)]
@@ -807,6 +814,7 @@ def compile(
         enable_profiling: bool,
         enable_haddock: bool,
         md_file: Artifact,
+        worker: WorkerInfo | None = None,
         pkgname: str | None = None) -> CompileResultInfo:
     artifact_suffix = get_artifact_suffix(link_style, enable_profiling)
 
@@ -862,6 +870,7 @@ def compile(
             sources_deps = ctx.attrs.srcs_deps,
             srcs_envs = ctx.attrs.srcs_envs,
             toolchain_deps_by_name = toolchain_deps_by_name,
+            worker = worker,
         ),
     ))
 
diff --git a/haskell/haskell.bzl b/haskell/haskell.bzl
index 6bc1c0fee..b2a218ea0 100644
--- a/haskell/haskell.bzl
+++ b/haskell/haskell.bzl
@@ -9,6 +9,7 @@
 
 load("@prelude//utils:arglike.bzl", "ArgLike")
 load("@prelude//:paths.bzl", "paths")
+load("@prelude//cxx:link_groups_types.bzl", "LINK_GROUP_MAP_ATTR")
 load("@prelude//cxx:archive.bzl", "make_archive")
 load(
     "@prelude//cxx:cxx.bzl",
@@ -151,6 +152,8 @@ load(
 load("@prelude//utils:argfile.bzl", "at_argfile")
 load("@prelude//utils:set.bzl", "set")
 load("@prelude//utils:utils.bzl", "filter_and_map_idx", "flatten")
+load("@prelude//decls:native_common.bzl", "native_common")
+load("@prelude//decls:haskell_common.bzl", "haskell_common")
 
 HaskellIndexingTSet = transitive_set()
 
@@ -644,6 +647,7 @@ def _build_haskell_lib(
         enable_haddock = enable_haddock,
         md_file = md_file,
         pkgname = pkgname,
+        worker = _persistent_worker(ctx),
     )
     solibs = {}
     artifact_suffix = get_artifact_suffix(link_style, enable_profiling)
@@ -1213,6 +1217,7 @@ def haskell_binary_impl(ctx: AnalysisContext) -> list[Provider]:
         enable_profiling = enable_profiling,
         enable_haddock = False,
         md_file = md_file,
+        worker = _persistent_worker(ctx),
     )
 
     haskell_toolchain = ctx.attrs._haskell_toolchain[HaskellToolchainInfo]
@@ -1474,3 +1479,66 @@ def _haskell_module_sub_targets(*, compiled, link_style, enable_profiling):
             if o.extension[1:] == osuf
         })],
     }
+
+worker = anon_rule(
+    impl = haskell_binary_impl,
+    attrs = {
+        "_cxx_toolchain": attrs.dep(),
+        "_generate_target_metadata": attrs.dep(providers = [RunInfo]),
+        "_ghc_wrapper": attrs.dep(providers = [RunInfo]),
+        "_haskell_toolchain": attrs.dep(providers = [HaskellToolchainInfo]),
+        "compiler_flags": attrs.list(attrs.string(), default = []),
+        "deps": attrs.list(attrs.dep()),
+        "enable_profiling": attrs.default_only(attrs.bool(default = False)),
+        "external_tools": attrs.list(attrs.dep(), default = []),
+        "link_group_map": LINK_GROUP_MAP_ATTR,
+        "linker_flags": attrs.list(attrs.string(), default = []),
+        "platform_deps": attrs.list(attrs.dep(), default = []),
+        "srcs": attrs.list(attrs.source()),
+        "srcs_deps": attrs.dict(attrs.string(), attrs.dep(), default = {}),
+        "srcs_envs": attrs.dict(attrs.string(), attrs.string(), default = {}),
+        "template_deps": attrs.list(attrs.dep(), default = []),
+        # N.B. the _worker_* attrs are only treated by the call site of the anon_target
+        "_worker_deps": attrs.default_only(attrs.list(attrs.dep(), default = [])),
+        "_worker_srcs": attrs.default_only(attrs.list(attrs.source(), default = [])),
+    }
+    | haskell_common.use_argsfile_at_link_arg()
+    | native_common.link_style(),
+    artifact_promise_mappings = {
+        "worker": lambda x: x[DefaultInfo].default_outputs[0],
+    },
+)
+
+def _persistent_worker(ctx: AnalysisContext) -> WorkerInfo | None:
+    if ctx.label.cell == "prelude":
+        return None
+
+    if not ctx.attrs._haskell_toolchain[HaskellToolchainInfo].use_worker:
+        return None
+
+    worker_target = ctx.actions.anon_target(
+        worker,
+        {
+            "_cxx_toolchain": ctx.attrs._cxx_toolchain,
+            "_generate_target_metadata": ctx.attrs._generate_target_metadata,
+            "_ghc_wrapper": ctx.attrs._ghc_wrapper,
+            "_haskell_toolchain": ctx.attrs._haskell_toolchain,
+            "deps": ctx.attrs._worker_deps,
+            "link_style": "shared",
+            "name": "prelude//haskell:worker",
+            "srcs": ctx.attrs._worker_srcs,
+            "compiler_flags": ctx.attrs._worker_compiler_flags + [
+                "-O2",
+            ],
+            "linker_flags": ctx.attrs._worker_compiler_flags + [
+                "-dynamic",
+                "-rtsopts=all",
+                "-with-rtsopts=-K512M -H -I5 -T",
+                "-threaded",
+                "-O2",
+            ],
+            "use_argsfile_at_link": False,
+        },
+    )
+    return WorkerInfo(worker_target.artifact("worker"))
+
diff --git a/haskell/toolchain.bzl b/haskell/toolchain.bzl
index f57d6d161..d4a3eae5b 100644
--- a/haskell/toolchain.bzl
+++ b/haskell/toolchain.bzl
@@ -40,6 +40,8 @@ HaskellToolchainInfo = provider(
         "cache_links": provider_field(typing.Any, default = None),
         "script_template_processor": provider_field(typing.Any, default = None),
         "packages": provider_field(typing.Any, default = None),
+        "use_worker": provider_field(bool, default = False),
+        "ghc_dir": provider_field(typing.Any, default = None),
     },
 )
 
diff --git a/haskell/tools/ghc_wrapper.py b/haskell/tools/ghc_wrapper.py
index 0a1c20f2d..6a255a6a7 100755
--- a/haskell/tools/ghc_wrapper.py
+++ b/haskell/tools/ghc_wrapper.py
@@ -39,6 +39,9 @@ def main():
     parser.add_argument(
         "--ghc", required=True, type=str, help="Path to the Haskell compiler GHC."
     )
+    parser.add_argument(
+        "--ghc-dir", type=str, help="Worker option"
+    )
     parser.add_argument(
         "--abi-out",
         required=True,
diff --git a/haskell/worker/BUCK b/haskell/worker/BUCK
new file mode 100644
index 000000000..232b24429
--- /dev/null
+++ b/haskell/worker/BUCK
@@ -0,0 +1,3 @@
+load(":worker.bzl", "worker_libs")
+
+[haskell_toolchain_library(name = pkg, visibility = ["PUBLIC"]) for pkg in worker_libs]
diff --git a/haskell/worker/impl b/haskell/worker/impl
new file mode 160000
index 000000000..dadddf43d
--- /dev/null
+++ b/haskell/worker/impl
@@ -0,0 +1 @@
+Subproject commit dadddf43dac15881b203be822c3192c76366bb07
diff --git a/haskell/worker/worker.bzl b/haskell/worker/worker.bzl
new file mode 100644
index 000000000..b02f56854
--- /dev/null
+++ b/haskell/worker/worker.bzl
@@ -0,0 +1,41 @@
+worker_libs = [
+    "base",
+    "bytestring",
+    "containers",
+    "deepseq",
+    "exceptions",
+    "filepath",
+    "ghc",
+    "grpc-haskell",
+    "proto3-suite",
+    "proto3-wire",
+    "text",
+    "vector",
+    "unix",
+]
+
+worker_srcs = [
+    "@prelude//haskell/worker/impl/plugin/src:Internal/AbiHash.hs",
+    "@prelude//haskell/worker/impl/plugin/src:Internal/Args.hs",
+    "@prelude//haskell/worker/impl/plugin/src:Internal/Cache.hs",
+    "@prelude//haskell/worker/impl/plugin/src:Internal/Compile.hs",
+    "@prelude//haskell/worker/impl/plugin/src:Internal/Error.hs",
+    "@prelude//haskell/worker/impl/plugin/src:Internal/Log.hs",
+    "@prelude//haskell/worker/impl/plugin/src:Internal/Session.hs",
+    "@prelude//haskell/worker/impl/buck-worker:Args.hs",
+    "@prelude//haskell/worker/impl/buck-worker:Main.hs",
+    "@prelude//haskell/worker/impl/buck-worker:BuckWorker.hs",
+]
+
+worker_flags = [
+    "-Wall",
+    "-XGHC2021",
+    "-XBlockArguments",
+    "-XDerivingStrategies",
+    "-XRecordWildCards",
+    "-XDuplicateRecordFields",
+    "-XOverloadedRecordDot",
+    "-XStrictData",
+    "-XNoFieldSelectors",
+    "-XLambdaCase",
+]