diff --git a/go.mod b/go.mod
index ed1bddc..197bc3a 100644
--- a/go.mod
+++ b/go.mod
@@ -1,5 +1,5 @@
 module moul.io/http2curl/v2
 
-go 1.13
+go 1.16
 
 require github.com/tailscale/depaware v0.0.0-20210622194025-720c4b409502
diff --git a/go.sum b/go.sum
index 73cc17a..a93ac25 100644
--- a/go.sum
+++ b/go.sum
@@ -1,13 +1,10 @@
-github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/pkg/diff v0.0.0-20200914180035-5b29258ca4f7 h1:+/+DxvQaYifJ+grD4klzrS5y+KJXldn/2YTl5JG+vZ8=
 github.com/pkg/diff v0.0.0-20200914180035-5b29258ca4f7/go.mod h1:zO8QMzTeZd5cpnIkz/Gn6iK0jDfGicM1nynOkkPIl28=
-github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/sergi/go-diff v1.0.0 h1:Kpca3qRNrduNnOQeazBd0ysaKrUJiIuISHxogkT9RPQ=
 github.com/sergi/go-diff v1.0.0/go.mod h1:0CfEIISq7TuYL3j771MWULgwwjU+GofnZX9QAmXWZgo=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
-github.com/stretchr/testify v1.4.0 h1:2E4SXV/wtOkTonXsotYi4li6zVWxYlZuYNCXe9XRJyk=
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
 github.com/tailscale/depaware v0.0.0-20210622194025-720c4b409502 h1:34icjjmqJ2HPjrSuJYEkdZ+0ItmGQAQ75cRHIiftIyE=
 github.com/tailscale/depaware v0.0.0-20210622194025-720c4b409502/go.mod h1:p9lPsd+cx33L3H9nNoecRRxPssFKUwwI50I3pZ0yT+8=
@@ -36,7 +33,5 @@ golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8T
 golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1 h1:go1bK/D/BFZV2I8cIQd1NKEZ+0owSTG1fDTci4IqFcE=
 golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
-gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/yaml.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
diff --git a/http2curl.go b/http2curl.go
index df21c19..c28ae4c 100644
--- a/http2curl.go
+++ b/http2curl.go
@@ -3,7 +3,7 @@ package http2curl
 import (
 	"bytes"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"sort"
 	"strings"
@@ -23,7 +23,7 @@ func (c *CurlCommand) String() string {
 }
 
 func bashEscape(str string) string {
-	return `'` + strings.Replace(str, `'`, `'\''`, -1) + `'`
+	return `'` + strings.ReplaceAll(str, `'`, `'\''`) + `'`
 }
 
 // GetCurlCommand returns a CurlCommand corresponding to an http.Request
@@ -59,7 +59,7 @@ func GetCurlCommand(req *http.Request) (*CurlCommand, error) {
 			return nil, fmt.Errorf("getCurlCommand: buffer read from body error: %w", err)
 		}
 		// reset body for potential re-reads
-		req.Body = ioutil.NopCloser(bytes.NewBuffer(buff.Bytes()))
+		req.Body = io.NopCloser(bytes.NewBuffer(buff.Bytes()))
 		if len(buff.String()) > 0 {
 			bodyEscaped := bashEscape(buff.String())
 			command.append("-d", bodyEscaped)
diff --git a/http2curl_test.go b/http2curl_test.go
index 544dbca..7195028 100644
--- a/http2curl_test.go
+++ b/http2curl_test.go
@@ -3,7 +3,7 @@ package http2curl
 import (
 	"bytes"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"net/http/httptest"
 	"net/url"
@@ -18,7 +18,7 @@ func ExampleGetCurlCommand() {
 	form.Add("name", "Hudson")
 	body := form.Encode()
 
-	req, _ := http.NewRequest(http.MethodPost, "http://foo.com/cats", ioutil.NopCloser(bytes.NewBufferString(body)))
+	req, _ := http.NewRequest(http.MethodPost, "http://foo.com/cats", io.NopCloser(bytes.NewBufferString(body)))
 	req.Header.Set("API_KEY", "123")
 
 	command, _ := GetCurlCommand(req)
@@ -149,7 +149,7 @@ func BenchmarkGetCurlCommand(b *testing.B) {
 	for i := 0; i <= b.N; i++ {
 		form.Add("number", strconv.Itoa(i))
 		body := form.Encode()
-		req, _ := http.NewRequest(http.MethodPost, "http://foo.com", ioutil.NopCloser(bytes.NewBufferString(body)))
+		req, _ := http.NewRequest(http.MethodPost, "http://foo.com", io.NopCloser(bytes.NewBufferString(body)))
 		_, err := GetCurlCommand(req)
 		if err != nil {
 			panic(err)
@@ -172,7 +172,7 @@ func TestGetCurlCommand_serverSide(t *testing.T) {
 		t.Error(err)
 	}
 	defer resp.Body.Close()
-	data, err := ioutil.ReadAll(resp.Body)
+	data, err := io.ReadAll(resp.Body)
 	if err != nil {
 		t.Error(err)
 	}