diff --git a/arguments/parser_test.go b/arguments/parser_test.go
index b231096..dbf2d86 100644
--- a/arguments/parser_test.go
+++ b/arguments/parser_test.go
@@ -1,11 +1,11 @@
-// +build !windows
+//go:build !windows
 
 package arguments_test
 
 import (
 	"errors"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"log"
 	"os"
 	"path"
@@ -41,7 +41,7 @@ func testParsingArguments(t *testing.T, when spec.G, it spec.S) {
 
 	it.Before(func() {
 		RegisterTestingT(t)
-		log.SetOutput(ioutil.Discard)
+		log.SetOutput(io.Discard)
 		workingDir = "/home/test-user/workspace"
 
 		evaler = func(input string) (string, error) {
diff --git a/arguments/parser_windows_test.go b/arguments/parser_windows_test.go
index 87574b8..1d4ff37 100644
--- a/arguments/parser_windows_test.go
+++ b/arguments/parser_windows_test.go
@@ -1,9 +1,9 @@
-// +build windows
+//go:build windows
 
 package arguments_test
 
 import (
-	"io/ioutil"
+	"io"
 	"log"
 	"os"
 	"path/filepath"
@@ -38,7 +38,7 @@ func testParsingArguments(t *testing.T, when spec.G, it spec.S) {
 
 	it.Before(func() {
 		RegisterTestingT(t)
-		log.SetOutput(ioutil.Discard)
+		log.SetOutput(io.Discard)
 		workingDir = "C:\\Users\\test-user\\workspace"
 
 		evaler = func(input string) (string, error) {
diff --git a/benchmark_test.go b/benchmark_test.go
index c46aa6f..ea966fe 100644
--- a/benchmark_test.go
+++ b/benchmark_test.go
@@ -1,7 +1,7 @@
 package main
 
 import (
-	"io/ioutil"
+	"io"
 	"log"
 	"path/filepath"
 	"testing"
@@ -16,7 +16,7 @@ func BenchmarkDoGenerate(b *testing.B) {
 	if err != nil {
 		b.Fatal(err)
 	}
-	log.SetOutput(ioutil.Discard)
+	log.SetOutput(io.Discard)
 
 	args := &arguments.ParsedArguments{
 		GenerateInterfaceAndShimFromPackageDirectory: false,
diff --git a/command/runner.go b/command/runner.go
index a4e6b7a..161fc4b 100644
--- a/command/runner.go
+++ b/command/runner.go
@@ -3,7 +3,6 @@ package command
 import (
 	"fmt"
 	"go/build"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"sort"
@@ -74,7 +73,7 @@ func generateModeInvocations(cwd string) ([]Invocation, error) {
 }
 
 func invocationsInFile(dir string, file string) ([]Invocation, error) {
-	str, err := ioutil.ReadFile(filepath.Join(dir, file))
+	str, err := os.ReadFile(filepath.Join(dir, file))
 	if err != nil {
 		return nil, err
 	}
diff --git a/generator/file_reader.go b/generator/file_reader.go
index 1a4f7eb..8e0e77d 100644
--- a/generator/file_reader.go
+++ b/generator/file_reader.go
@@ -2,7 +2,6 @@ package generator
 
 import (
 	"io"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 )
@@ -28,7 +27,7 @@ func (open Opener) readString(path string) (string, error) {
 	}
 	defer f.Close()
 
-	b, err := ioutil.ReadAll(f)
+	b, err := io.ReadAll(f)
 	if err != nil {
 		return "", err
 	}
diff --git a/generator/file_reader_test.go b/generator/file_reader_test.go
index d8153f5..f0edbed 100644
--- a/generator/file_reader_test.go
+++ b/generator/file_reader_test.go
@@ -3,7 +3,6 @@ package generator_test
 import (
 	"fmt"
 	"io"
-	"io/ioutil"
 	"reflect"
 	"strings"
 	"testing"
@@ -153,13 +152,13 @@ func openReturningErr(err string) generator.Opener {
 }
 func openReturningReader(content string) generator.Opener {
 	return func(_ string) (io.ReadCloser, error) {
-		return ioutil.NopCloser(strings.NewReader(content)), nil
+		return io.NopCloser(strings.NewReader(content)), nil
 	}
 }
 func openReturningFailingReader(err string) generator.Opener {
 	return func(_ string) (io.ReadCloser, error) {
 		r := &erroringReader{
-			reader: ioutil.NopCloser(strings.NewReader("some random file content")),
+			reader: io.NopCloser(strings.NewReader("some random file content")),
 			err:    fmt.Errorf(err),
 		}
 		return r, nil
diff --git a/generator/generator_internals_test.go b/generator/generator_internals_test.go
index f524608..0fb1959 100644
--- a/generator/generator_internals_test.go
+++ b/generator/generator_internals_test.go
@@ -1,7 +1,7 @@
 package generator
 
 import (
-	"io/ioutil"
+	"io"
 	"log"
 	"runtime"
 	"testing"
@@ -13,7 +13,7 @@ import (
 )
 
 func TestGenerator(t *testing.T) {
-	log.SetOutput(ioutil.Discard) // Comment this out to see verbose log output
+	log.SetOutput(io.Discard) // Comment this out to see verbose log output
 	log.SetFlags(log.Llongfile)
 	spec.Run(t, "Generator", testGenerator, spec.Report(report.Terminal{}))
 }
diff --git a/integration/roundtrip_module_test.go b/integration/roundtrip_module_test.go
index ffbd44d..499b25b 100644
--- a/integration/roundtrip_module_test.go
+++ b/integration/roundtrip_module_test.go
@@ -1,3 +1,4 @@
+//go:build go1.11
 // +build go1.11
 
 package integration_test
diff --git a/integration/roundtrip_test.go b/integration/roundtrip_test.go
index e62dbb2..55840d0 100644
--- a/integration/roundtrip_test.go
+++ b/integration/roundtrip_test.go
@@ -3,7 +3,7 @@ package integration_test
 import (
 	"fmt"
 	"go/build"
-	"io/ioutil"
+	"io"
 	"log"
 	"os"
 	"path/filepath"
@@ -17,7 +17,7 @@ import (
 )
 
 func runTests(t *testing.T, when spec.G, it spec.S) {
-	log.SetOutput(ioutil.Discard) // Comment this out to see verbose log output
+	log.SetOutput(io.Discard) // Comment this out to see verbose log output
 	log.SetFlags(log.Llongfile)
 	var (
 		baseDir             string
@@ -41,7 +41,7 @@ func runTests(t *testing.T, when spec.G, it spec.S) {
 		originalGopath = os.Getenv("GOPATH")
 		originalBuildGopath = build.Default.GOPATH
 		var err error
-		testDir, err = ioutil.TempDir("", "counterfeiter-integration")
+		testDir, err = os.MkdirTemp("", "counterfeiter-integration")
 		Expect(err).NotTo(HaveOccurred())
 		os.Unsetenv("GOPATH")
 		baseDir = testDir
@@ -63,14 +63,14 @@ func runTests(t *testing.T, when spec.G, it spec.S) {
 
 			err = os.MkdirAll(dir, 0777)
 			Expect(err).ToNot(HaveOccurred())
-			b, err := ioutil.ReadFile(filepath.Join(relativeDir, name))
+			b, err := os.ReadFile(filepath.Join(relativeDir, name))
 			Expect(err).ToNot(HaveOccurred())
-			err = ioutil.WriteFile(filepath.Join(baseDir, name), b, 0755)
+			err = os.WriteFile(filepath.Join(baseDir, name), b, 0755)
 			Expect(err).ToNot(HaveOccurred())
 		}
 		initModuleFunc = func() {
 			copyFileFunc("blank.go")
-			err := ioutil.WriteFile(filepath.Join(baseDir, "go.mod"), []byte("module github.com/maxbrunsfeld/counterfeiter/v6/fixtures"), 0755)
+			err := os.WriteFile(filepath.Join(baseDir, "go.mod"), []byte("module github.com/maxbrunsfeld/counterfeiter/v6/fixtures"), 0755)
 			Expect(err).ToNot(HaveOccurred())
 		}
 		// Set this to true to write the output of tests to the testdata/output
@@ -115,7 +115,7 @@ func runTests(t *testing.T, when spec.G, it spec.S) {
 				}
 				WriteOutput(b, filepath.Join(baseDir, "fixturesfakes", "fake_write_closer."+variant+".go"))
 				RunBuild(baseDir)
-				b2, err := ioutil.ReadFile(filepath.Join("testdata", "expected_fake_writecloser."+variant+".txt"))
+				b2, err := os.ReadFile(filepath.Join("testdata", "expected_fake_writecloser."+variant+".txt"))
 				Expect(err).NotTo(HaveOccurred())
 				Expect(string(b2)).To(Equal(string(b)))
 			})
diff --git a/integration/util_test.go b/integration/util_test.go
index 9f6f039..6490f30 100644
--- a/integration/util_test.go
+++ b/integration/util_test.go
@@ -3,17 +3,18 @@ package integration_test
 import (
 	"bytes"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
 
+	"io/fs"
+
 	. "github.com/onsi/gomega"
 )
 
 func WriteOutput(b []byte, file string) {
-	os.MkdirAll(filepath.Dir(file), 0700)
-	ioutil.WriteFile(file, b, 0600)
+	_ = os.MkdirAll(filepath.Dir(file), 0700)
+	_ = os.WriteFile(file, b, fs.FileMode(0600))
 }
 
 func RunBuild(baseDir string) {
diff --git a/main.go b/main.go
index 0efb3f8..b9b84ce 100644
--- a/main.go
+++ b/main.go
@@ -4,7 +4,7 @@ import (
 	"errors"
 	"fmt"
 	"go/format"
-	"io/ioutil"
+	"io"
 	"log"
 	"os"
 	"path/filepath"
@@ -44,7 +44,7 @@ func run() error {
 
 	log.SetFlags(log.Lshortfile)
 	if !isDebug() {
-		log.SetOutput(ioutil.Discard)
+		log.SetOutput(io.Discard)
 	}
 
 	cwd, err := os.Getwd()