diff --git a/.github/workflows/go.yaml b/.github/workflows/go.yaml
index 9d359da..fa1ae7c 100644
--- a/.github/workflows/go.yaml
+++ b/.github/workflows/go.yaml
@@ -14,7 +14,7 @@ jobs:
       - uses: actions/checkout@v2
       - uses: actions/setup-go@v2
         with:
-          go-version: 1.18.x
+          go-version: 1.20.x
       - name: Cache
         uses: actions/cache@v2
         with:
@@ -35,7 +35,7 @@ jobs:
       - uses: actions/checkout@v2
       - uses: actions/setup-go@v2
         with:
-          go-version: 1.18.x
+          go-version: 1.20.x
       - run: go install golang.org/dl/gotip@latest
       - run: gotip download
       - run: gotip version
diff --git a/README.md b/README.md
index a781d59..e12b583 100644
--- a/README.md
+++ b/README.md
@@ -130,7 +130,7 @@ For applying suggested fix, use `-apply` flag, instead of `-fix`.
 
 ## Development
 
-Go 1.18+
+Go 1.20+
 
 ### Running test
 
diff --git a/go.mod b/go.mod
index abb4a54..aa798d4 100644
--- a/go.mod
+++ b/go.mod
@@ -1,13 +1,13 @@
 module github.com/orijtech/structslop
 
-go 1.18
+go 1.20
 
 require (
-	github.com/dave/dst v0.27.0
-	golang.org/x/tools v0.1.11
+	github.com/dave/dst v0.27.2
+	golang.org/x/tools v0.8.0
 )
 
 require (
-	golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4 // indirect
-	golang.org/x/sys v0.0.0-20220704084225-05e143d24a9e // indirect
+	golang.org/x/mod v0.10.0 // indirect
+	golang.org/x/sys v0.7.0 // indirect
 )
diff --git a/go.sum b/go.sum
index 975ce2e..0686992 100644
--- a/go.sum
+++ b/go.sum
@@ -1,10 +1,11 @@
-github.com/dave/dst v0.27.0 h1:vh51Zc/7bH5YfbspFsEizLuQ1xm6zDQWMJiIlZhiNQ4=
-github.com/dave/dst v0.27.0/go.mod h1:eF/UOVnw9Ech3NkZFCdtujtISJFRYf11+I93p+RI5S4=
+github.com/dave/dst v0.27.2 h1:4Y5VFTkhGLC1oddtNwuxxe36pnyLxMFXT51FOzH8Ekc=
+github.com/dave/dst v0.27.2/go.mod h1:jHh6EOibnHgcUW3WjKHisiooEkYwqpHLBSX1iOBhEyc=
 github.com/dave/jennifer v1.5.0 h1:HmgPN93bVDpkQyYbqhCHj5QlgvUkvEOzMyEvKLgCRrg=
 github.com/sergi/go-diff v1.2.0 h1:XU+rvMAioB0UC3q1MFrIQy4Vo5/4VsRDQQXHsEya6xQ=
-golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4 h1:6zppjxzCulZykYSLyVDYbneBfbaBIQPYMevg0bEwv2s=
-golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4/go.mod h1:jJ57K6gSWd91VN4djpZkiMVwK6gcyfeH4XE8wZrZaV4=
-golang.org/x/sys v0.0.0-20220704084225-05e143d24a9e h1:CsOuNlbOuf0mzxJIefr6Q4uAUetRUwZE4qt7VfzP+xo=
-golang.org/x/sys v0.0.0-20220704084225-05e143d24a9e/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/tools v0.1.11 h1:loJ25fNOEhSXfHrpoGj91eCUThwdNX6u24rO1xnNteY=
-golang.org/x/tools v0.1.11/go.mod h1:SgwaegtQh8clINPpECJMqnxLv9I09HLqnW3RMqW0CA4=
+golang.org/x/mod v0.10.0 h1:lFO9qtOdlre5W1jxS3r/4szv2/6iXxScdzjoBMXNhYk=
+golang.org/x/mod v0.10.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
+golang.org/x/sync v0.1.0 h1:wsuoTGHzEhffawBOhz5CYhcrV4IdKZbEyZjBMuTp12o=
+golang.org/x/sys v0.7.0 h1:3jlCCIQZPdOYu1h8BkNvLz8Kgwtae2cagcG/VamtZRU=
+golang.org/x/sys v0.7.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/tools v0.8.0 h1:vSDcovVPld282ceKgDimkRSC8kpaH1dgyc9UMzlt84Y=
+golang.org/x/tools v0.8.0/go.mod h1:JxBZ99ISMI5ViVkT1tr6tdNmXeTrcpVSD3vZ1RsRdN4=
diff --git a/structslop.go b/structslop.go
index 7a2d762..df1d571 100644
--- a/structslop.go
+++ b/structslop.go
@@ -23,7 +23,6 @@ import (
 	"go/parser"
 	"go/token"
 	"go/types"
-	"io/ioutil"
 	"os"
 	"sort"
 	"strings"
@@ -187,7 +186,7 @@ func run(pass *analysis.Pass) (interface{}, error) {
 		if err := fi.Close(); err != nil {
 			_, _ = fmt.Fprintf(os.Stderr, "failed to close file: %v", err)
 		}
-		if err := ioutil.WriteFile(fn, content, st.Mode()); err != nil {
+		if err := os.WriteFile(fn, content, st.Mode()); err != nil {
 			_, _ = fmt.Fprintf(os.Stderr, "failed to write suggested fix to file: %v", err)
 		}
 	}
diff --git a/structslop_test.go b/structslop_test.go
index 699c902..4a2eb1b 100644
--- a/structslop_test.go
+++ b/structslop_test.go
@@ -16,7 +16,6 @@ package structslop_test
 
 import (
 	"bytes"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"strings"
@@ -34,14 +33,14 @@ func Test(t *testing.T) {
 
 func TestApply(t *testing.T) {
 	dir := strings.Join([]string{".", "testdata", "src"}, string(os.PathSeparator))
-	tmpdir, err := ioutil.TempDir(dir, "structslop-test-apply-")
+	tmpdir, err := os.MkdirTemp(dir, "structslop-test-apply-")
 	if err != nil {
 		t.Fatal(err)
 	}
 	defer os.RemoveAll(tmpdir)
 	fn := filepath.Join(tmpdir, "p.go")
-	src, _ := ioutil.ReadFile(filepath.Join(".", "testdata", "src", "struct", "p.go"))
-	if err := ioutil.WriteFile(fn, src, 0644); err != nil {
+	src, _ := os.ReadFile(filepath.Join(".", "testdata", "src", "struct", "p.go"))
+	if err := os.WriteFile(fn, src, 0644); err != nil {
 		t.Fatal(err)
 	}
 	testdata := analysistest.TestData()
@@ -50,8 +49,8 @@ func TestApply(t *testing.T) {
 		_ = structslop.Analyzer.Flags.Set("apply", "false")
 	}()
 	analysistest.Run(t, testdata, structslop.Analyzer, filepath.Base(tmpdir))
-	got, _ := ioutil.ReadFile(fn)
-	expected, _ := ioutil.ReadFile(filepath.Join(".", "testdata", "src", "struct", "p.go.golden"))
+	got, _ := os.ReadFile(fn)
+	expected, _ := os.ReadFile(filepath.Join(".", "testdata", "src", "struct", "p.go.golden"))
 	if !bytes.Equal(expected, got) {
 		t.Errorf("unexpected suggested fix, want:\n%s\ngot:\n%s\n", string(expected), string(got))
 	}