diff --git a/arm/armasm/decode_test.go b/arm/armasm/decode_test.go
index e2d9127..80e02df 100644
--- a/arm/armasm/decode_test.go
+++ b/arm/armasm/decode_test.go
@@ -6,14 +6,14 @@ package armasm
 
 import (
 	"encoding/hex"
-	"io/ioutil"
+	"os"
 	"strconv"
 	"strings"
 	"testing"
 )
 
 func TestDecode(t *testing.T) {
-	data, err := ioutil.ReadFile("testdata/decode.txt")
+	data, err := os.ReadFile("testdata/decode.txt")
 	if err != nil {
 		t.Fatal(err)
 	}
diff --git a/arm/armasm/ext_test.go b/arm/armasm/ext_test.go
index f075862..c72ab1b 100644
--- a/arm/armasm/ext_test.go
+++ b/arm/armasm/ext_test.go
@@ -14,7 +14,6 @@ import (
 	"flag"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"log"
 	"math/rand"
 	"os"
@@ -190,7 +189,7 @@ const start = 0x8000 // start address of text
 // starting at offset start. That file is intended to be the input to
 // the external disassembler.
 func writeInst(generate func(func([]byte))) (file string, f *os.File, size int, err error) {
-	f, err = ioutil.TempFile("", "armasm")
+	f, err = os.CreateTemp("", "armasm")
 	if err != nil {
 		return
 	}
@@ -568,7 +567,7 @@ func hexCases(t *testing.T, encoded string) func(func([]byte)) {
 // It only uses the inputs; it ignores the answers recorded in that file.
 func testdataCases(t *testing.T) func(func([]byte)) {
 	var codes [][]byte
-	data, err := ioutil.ReadFile("testdata/decode.txt")
+	data, err := os.ReadFile("testdata/decode.txt")
 	if err != nil {
 		t.Fatal(err)
 	}
diff --git a/arm/armspec/specmap.go b/arm/armspec/specmap.go
index 973030f..b99586d 100644
--- a/arm/armspec/specmap.go
+++ b/arm/armspec/specmap.go
@@ -9,7 +9,6 @@ package main
 import (
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
 	"log"
 	"os"
 	"regexp"
@@ -33,7 +32,7 @@ type Inst struct {
 }
 
 func main() {
-	data, err := ioutil.ReadFile("spec.json")
+	data, err := os.ReadFile("spec.json")
 	if err != nil {
 		log.Fatal(err)
 	}
diff --git a/arm64/arm64asm/decode_test.go b/arm64/arm64asm/decode_test.go
index 26eb6ae..aa13997 100644
--- a/arm64/arm64asm/decode_test.go
+++ b/arm64/arm64asm/decode_test.go
@@ -6,7 +6,7 @@ package arm64asm
 
 import (
 	"encoding/hex"
-	"io/ioutil"
+	"os"
 	"path/filepath"
 	"strings"
 	"testing"
@@ -14,7 +14,7 @@ import (
 
 func testDecode(t *testing.T, syntax string) {
 	input := filepath.Join("testdata", syntax+"cases.txt")
-	data, err := ioutil.ReadFile(input)
+	data, err := os.ReadFile(input)
 	if err != nil {
 		t.Fatal(err)
 	}
diff --git a/arm64/arm64asm/ext_test.go b/arm64/arm64asm/ext_test.go
index f0d18e9..362276a 100644
--- a/arm64/arm64asm/ext_test.go
+++ b/arm64/arm64asm/ext_test.go
@@ -15,7 +15,6 @@ import (
 	"flag"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"log"
 	"math/rand"
 	"os"
@@ -214,7 +213,7 @@ const start = 0x8000
 // starting at offset start. That file is intended to be the input to
 // the external disassembler.
 func writeInst(generate func(func([]byte))) (file string, f *os.File, size int, err error) {
-	f, err = ioutil.TempFile("", "arm64asm")
+	f, err = os.CreateTemp("", "arm64asm")
 	if err != nil {
 		return
 	}
@@ -501,7 +500,7 @@ func doFuzzy(inst *InstJson, Ninst int) {
 // JSONCases generates ARM64 instructions according to inst.json.
 func JSONCases(t *testing.T) func(func([]byte)) {
 	return func(try func([]byte)) {
-		data, err := ioutil.ReadFile("inst.json")
+		data, err := os.ReadFile("inst.json")
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -565,7 +564,7 @@ func hexCases(t *testing.T, encoded string) func(func([]byte)) {
 func testdataCases(t *testing.T, syntax string) func(func([]byte)) {
 	var codes [][]byte
 	input := filepath.Join("testdata", syntax+"cases.txt")
-	data, err := ioutil.ReadFile(input)
+	data, err := os.ReadFile(input)
 	if err != nil {
 		t.Fatal(err)
 	}
diff --git a/arm64/arm64gen/sysreggen.go b/arm64/arm64gen/sysreggen.go
index 5c42532..dd83f23 100644
--- a/arm64/arm64gen/sysreggen.go
+++ b/arm64/arm64gen/sysreggen.go
@@ -22,7 +22,7 @@ import (
 	"encoding/xml"
 	"flag"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"log"
 	"os"
 	"path/filepath"
@@ -124,7 +124,7 @@ func main() {
 	check(err)
 	defer out.Close()
 
-	files, err := ioutil.ReadDir(*xmlfolder)
+	files, err := os.ReadDir(*xmlfolder)
 	check(err)
 
 	var systemregs []SystemReg
@@ -133,7 +133,7 @@ func main() {
 	for _, file := range files {
 		xmlFile, err := os.Open(filepath.Join(*xmlfolder, file.Name()))
 		check(err)
-		value, err := ioutil.ReadAll(xmlFile)
+		value, err := io.ReadAll(xmlFile)
 		check(err)
 
 		var regpage RegisterPage
diff --git a/loong64/loong64asm/decode_test.go b/loong64/loong64asm/decode_test.go
index 74a3277..e485cb8 100644
--- a/loong64/loong64asm/decode_test.go
+++ b/loong64/loong64asm/decode_test.go
@@ -6,7 +6,7 @@ package loong64asm
 
 import (
 	"encoding/hex"
-	"io/ioutil"
+	"os"
 	"path/filepath"
 	"strings"
 	"testing"
@@ -14,7 +14,7 @@ import (
 
 func testDecode(t *testing.T, syntax string) {
 	input := filepath.Join("testdata", syntax+"cases.txt")
-	data, err := ioutil.ReadFile(input)
+	data, err := os.ReadFile(input)
 	if err != nil {
 		t.Fatal(err)
 	}
diff --git a/loong64/loong64asm/ext_test.go b/loong64/loong64asm/ext_test.go
index 5e73c80..14235c6 100644
--- a/loong64/loong64asm/ext_test.go
+++ b/loong64/loong64asm/ext_test.go
@@ -13,7 +13,6 @@ import (
 	"flag"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"log"
 	"math/rand"
 	"os"
@@ -187,7 +186,7 @@ const start = 0x8000
 // starting at offset start. That file is intended to be the input to
 // the external disassembler.
 func writeInst(generate func(func([]byte))) (file string, f *os.File, size int, err error) {
-	f, err = ioutil.TempFile("", "loong64asm")
+	f, err = os.CreateTemp("", "loong64asm")
 	if err != nil {
 		return
 	}
@@ -371,7 +370,7 @@ func hexCases(t *testing.T, encoded string) func(func([]byte)) {
 func testdataCases(t *testing.T, syntax string) func(func([]byte)) {
 	var codes [][]byte
 	input := filepath.Join("testdata", syntax+"cases.txt")
-	data, err := ioutil.ReadFile(input)
+	data, err := os.ReadFile(input)
 	if err != nil {
 		t.Fatal(err)
 	}
diff --git a/ppc64/ppc64asm/decode_test.go b/ppc64/ppc64asm/decode_test.go
index 83a3acd..4fda8ec 100644
--- a/ppc64/ppc64asm/decode_test.go
+++ b/ppc64/ppc64asm/decode_test.go
@@ -7,14 +7,14 @@ package ppc64asm
 import (
 	"encoding/binary"
 	"encoding/hex"
-	"io/ioutil"
+	"os"
 	"path"
 	"strings"
 	"testing"
 )
 
 func TestDecode(t *testing.T) {
-	files, err := ioutil.ReadDir("testdata")
+	files, err := os.ReadDir("testdata")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -23,7 +23,7 @@ func TestDecode(t *testing.T) {
 			continue
 		}
 		filename := path.Join("testdata", f.Name())
-		data, err := ioutil.ReadFile(filename)
+		data, err := os.ReadFile(filename)
 		if err != nil {
 			t.Fatal(err)
 		}
diff --git a/ppc64/ppc64asm/ext_test.go b/ppc64/ppc64asm/ext_test.go
index 806701b..60428e6 100644
--- a/ppc64/ppc64asm/ext_test.go
+++ b/ppc64/ppc64asm/ext_test.go
@@ -15,7 +15,6 @@ import (
 	"flag"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"log"
 	"math/rand"
 	"os"
@@ -188,7 +187,7 @@ const start = 0x8000 // start address of text
 // starting at offset start. That file is intended to be the input to
 // the external disassembler.
 func writeInst(generate func(func([]byte))) (file string, f *os.File, size int, err error) {
-	f, err = ioutil.TempFile("", "ppc64asm")
+	f, err = os.CreateTemp("", "ppc64asm")
 	if err != nil {
 		return
 	}
@@ -494,7 +493,7 @@ func hexCases(t *testing.T, encoded string) func(func([]byte)) {
 // It only uses the inputs; it ignores the answers recorded in that file.
 func testdataCases(t *testing.T) func(func([]byte)) {
 	var codes [][]byte
-	data, err := ioutil.ReadFile("testdata/decode.txt")
+	data, err := os.ReadFile("testdata/decode.txt")
 	if err != nil {
 		t.Fatal(err)
 	}
diff --git a/riscv64/riscv64asm/ext_test.go b/riscv64/riscv64asm/ext_test.go
index 556cd01..c2e35ef 100644
--- a/riscv64/riscv64asm/ext_test.go
+++ b/riscv64/riscv64asm/ext_test.go
@@ -13,7 +13,6 @@ import (
 	"flag"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"log"
 	"math/rand"
 	"os"
@@ -189,7 +188,7 @@ const start = 0x8000
 // starting at offset start. That file is intended to be the input to
 // the external disassembler.
 func writeInst(generate func(func([]byte))) (file string, f *os.File, size int, err error) {
-	f, err = ioutil.TempFile("", "riscv64asm")
+	f, err = os.CreateTemp("", "riscv64asm")
 	if err != nil {
 		return
 	}
@@ -299,7 +298,7 @@ func hexCases(t *testing.T, encoded string) func(func([]byte)) {
 func testdataCases(t *testing.T, syntax string) func(func([]byte)) {
 	var codes [][]byte
 	input := filepath.Join("testdata", syntax+"cases.txt")
-	data, err := ioutil.ReadFile(input)
+	data, err := os.ReadFile(input)
 	if err != nil {
 		t.Fatal(err)
 	}
diff --git a/s390x/s390xasm/decode_test.go b/s390x/s390xasm/decode_test.go
index 047ebee..51dd5e7 100644
--- a/s390x/s390xasm/decode_test.go
+++ b/s390x/s390xasm/decode_test.go
@@ -6,14 +6,14 @@ package s390xasm
 
 import (
 	"encoding/hex"
-	"io/ioutil"
+	"os"
 	"path"
 	"strings"
 	"testing"
 )
 
 func TestDecode(t *testing.T) {
-	files, err := ioutil.ReadDir("testdata")
+	files, err := os.ReadDir("testdata")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -22,7 +22,7 @@ func TestDecode(t *testing.T) {
 			continue
 		}
 		filename := path.Join("testdata", f.Name())
-		data, err := ioutil.ReadFile(filename)
+		data, err := os.ReadFile(filename)
 		if err != nil {
 			t.Fatal(err)
 		}
diff --git a/x86/x86asm/decode_test.go b/x86/x86asm/decode_test.go
index 4543cd2..559556d 100644
--- a/x86/x86asm/decode_test.go
+++ b/x86/x86asm/decode_test.go
@@ -6,14 +6,14 @@ package x86asm
 
 import (
 	"encoding/hex"
-	"io/ioutil"
+	"os"
 	"strconv"
 	"strings"
 	"testing"
 )
 
 func TestDecode(t *testing.T) {
-	data, err := ioutil.ReadFile("testdata/decode.txt")
+	data, err := os.ReadFile("testdata/decode.txt")
 	if err != nil {
 		t.Fatal(err)
 	}
diff --git a/x86/x86asm/ext_test.go b/x86/x86asm/ext_test.go
index 2e31dd3..d198da8 100644
--- a/x86/x86asm/ext_test.go
+++ b/x86/x86asm/ext_test.go
@@ -13,7 +13,6 @@ import (
 	"flag"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"log"
 	"math/rand"
 	"os"
@@ -193,7 +192,7 @@ const start = 0x8000 // start address of text
 // starting at offset start. That file is intended to be the input to
 // the external disassembler.
 func writeInst(generate func(func([]byte))) (file string, f *os.File, size int, err error) {
-	f, err = ioutil.TempFile("", "x86map")
+	f, err = os.CreateTemp("", "x86map")
 	if err != nil {
 		return
 	}
@@ -524,7 +523,7 @@ func hexCases(t *testing.T, encoded string) func(func([]byte)) {
 // It only uses the inputs; it ignores the answers recorded in that file.
 func testdataCases(t *testing.T) func(func([]byte)) {
 	var codes [][]byte
-	data, err := ioutil.ReadFile("testdata/decode.txt")
+	data, err := os.ReadFile("testdata/decode.txt")
 	if err != nil {
 		t.Fatal(err)
 	}
diff --git a/x86/x86avxgen/avxgen_test.go b/x86/x86avxgen/avxgen_test.go
index e2f5b24..b1a9b76 100644
--- a/x86/x86avxgen/avxgen_test.go
+++ b/x86/x86avxgen/avxgen_test.go
@@ -6,7 +6,7 @@ package main
 
 import (
 	"bytes"
-	"io/ioutil"
+	"os"
 	"path/filepath"
 	"regexp"
 	"strings"
@@ -57,7 +57,7 @@ func TestOutput(t *testing.T) {
 	var testCases []testCase
 	{
 		opcodeRE := regexp.MustCompile(`as: ([A-Z][A-Z0-9]*)`)
-		data, err := ioutil.ReadFile(filepath.Join("testdata", "golden.txt"))
+		data, err := os.ReadFile(filepath.Join("testdata", "golden.txt"))
 		if err != nil {
 			t.Fatalf("read golden file: %v", err)
 		}
diff --git a/x86/xeddata/database.go b/x86/xeddata/database.go
index a6ec760..fa08d2f 100644
--- a/x86/xeddata/database.go
+++ b/x86/xeddata/database.go
@@ -9,7 +9,6 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"regexp"
@@ -212,7 +211,7 @@ func (db *Database) WidthSize(width string, m OperandSizeMode) string {
 }
 
 func parseWidths(r io.Reader) (map[string]*width, error) {
-	data, err := ioutil.ReadAll(r)
+	data, err := io.ReadAll(r)
 	if err != nil {
 		return nil, fmt.Errorf("parse widths: %v", err)
 	}
@@ -282,7 +281,7 @@ func parseExtraWidths(r io.Reader) (map[string]string, error) {
 }
 
 func parseStates(r io.Reader) (map[string]string, error) {
-	data, err := ioutil.ReadAll(r)
+	data, err := io.ReadAll(r)
 	if err != nil {
 		return nil, fmt.Errorf("parse states: %v", err)
 	}
@@ -303,7 +302,7 @@ func parseStates(r io.Reader) (map[string]string, error) {
 }
 
 func parseXtypes(r io.Reader) (map[string]*xtype, error) {
-	data, err := ioutil.ReadAll(r)
+	data, err := io.ReadAll(r)
 	if err != nil {
 		return nil, fmt.Errorf("parse xtypes: %v", err)
 	}
diff --git a/x86/xeddata/xeddata_test.go b/x86/xeddata/xeddata_test.go
index 8b64be4..6d05ee9 100644
--- a/x86/xeddata/xeddata_test.go
+++ b/x86/xeddata/xeddata_test.go
@@ -9,7 +9,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
-	"io/ioutil"
+	"os"
 	"path"
 	"reflect"
 	"strings"
@@ -401,7 +401,7 @@ func TestReader(t *testing.T) {
 
 	var tests []test
 	{
-		b, err := ioutil.ReadFile(path.Join("testdata", "xed_objects.txt"))
+		b, err := os.ReadFile(path.Join("testdata", "xed_objects.txt"))
 		if err != nil {
 			t.Fatal(err)
 		}