diff --git a/certificate/certificate.go b/certificate/certificate.go
index 6496720a..7ed6590d 100644
--- a/certificate/certificate.go
+++ b/certificate/certificate.go
@@ -8,7 +8,7 @@ import (
 	"crypto/x509"
 	"encoding/pem"
 	"errors"
-	"io/ioutil"
+	"os"
 	"strings"
 
 	"golang.org/x/crypto/pkcs12"
@@ -29,7 +29,7 @@ var (
 // Use "" as the password argument if the PKCS#12 certificate is not password
 // protected.
 func FromP12File(filename string, password string) (tls.Certificate, error) {
-	p12bytes, err := ioutil.ReadFile(filename)
+	p12bytes, err := os.ReadFile(filename)
 	if err != nil {
 		return tls.Certificate{}, err
 	}
@@ -62,7 +62,7 @@ func FromP12Bytes(bytes []byte, password string) (tls.Certificate, error) {
 // Use "" as the password argument if the PEM certificate is not password
 // protected.
 func FromPemFile(filename string, password string) (tls.Certificate, error) {
-	bytes, err := ioutil.ReadFile(filename)
+	bytes, err := os.ReadFile(filename)
 	if err != nil {
 		return tls.Certificate{}, err
 	}
diff --git a/certificate/certificate_test.go b/certificate/certificate_test.go
index b04eeac1..c52b3073 100644
--- a/certificate/certificate_test.go
+++ b/certificate/certificate_test.go
@@ -3,7 +3,7 @@ package certificate_test
 import (
 	"crypto/tls"
 	"errors"
-	"io/ioutil"
+	"os"
 	"testing"
 
 	"github.com/sideshow/apns2/certificate"
@@ -19,7 +19,7 @@ func TestValidCertificateFromP12File(t *testing.T) {
 }
 
 func TestValidCertificateFromP12Bytes(t *testing.T) {
-	bytes, _ := ioutil.ReadFile("_fixtures/certificate-valid.p12")
+	bytes, _ := os.ReadFile("_fixtures/certificate-valid.p12")
 	cer, err := certificate.FromP12Bytes(bytes, "")
 	assert.NoError(t, err)
 	assert.NotEqual(t, tls.Certificate{}, cer)
@@ -52,7 +52,7 @@ func TestValidCertificateFromPemFile(t *testing.T) {
 }
 
 func TestValidCertificateFromPemBytes(t *testing.T) {
-	bytes, _ := ioutil.ReadFile("_fixtures/certificate-valid.pem")
+	bytes, _ := os.ReadFile("_fixtures/certificate-valid.pem")
 	cer, err := certificate.FromPemBytes(bytes, "")
 	assert.NoError(t, err)
 	assert.NotEqual(t, tls.Certificate{}, cer)
@@ -65,7 +65,7 @@ func TestValidCertificateFromPemFileWithPKCS8PrivateKey(t *testing.T) {
 }
 
 func TestValidCertificateFromPemBytesWithPKCS8PrivateKey(t *testing.T) {
-	bytes, _ := ioutil.ReadFile("_fixtures/certificate-valid-pkcs8.pem")
+	bytes, _ := os.ReadFile("_fixtures/certificate-valid-pkcs8.pem")
 	cer, err := certificate.FromPemBytes(bytes, "")
 	assert.NoError(t, err)
 	assert.NotEqual(t, tls.Certificate{}, cer)
diff --git a/token/token.go b/token/token.go
index 26fec563..bf26e1a9 100644
--- a/token/token.go
+++ b/token/token.go
@@ -5,7 +5,7 @@ import (
 	"crypto/x509"
 	"encoding/pem"
 	"errors"
-	"io/ioutil"
+	"os"
 	"sync"
 	"time"
 
@@ -40,7 +40,7 @@ type Token struct {
 // AuthKeyFromFile loads a .p8 certificate from a local file and returns a
 // *ecdsa.PrivateKey.
 func AuthKeyFromFile(filename string) (*ecdsa.PrivateKey, error) {
-	bytes, err := ioutil.ReadFile(filename)
+	bytes, err := os.ReadFile(filename)
 	if err != nil {
 		return nil, err
 	}
diff --git a/token/token_test.go b/token/token_test.go
index ef3c6fd1..87a45aab 100644
--- a/token/token_test.go
+++ b/token/token_test.go
@@ -5,7 +5,7 @@ import (
 	"crypto/elliptic"
 	"crypto/rand"
 	"errors"
-	"io/ioutil"
+	"os"
 	"testing"
 	"time"
 
@@ -21,7 +21,7 @@ func TestValidTokenFromP8File(t *testing.T) {
 }
 
 func TestValidTokenFromP8Bytes(t *testing.T) {
-	bytes, _ := ioutil.ReadFile("_fixtures/authkey-valid.p8")
+	bytes, _ := os.ReadFile("_fixtures/authkey-valid.p8")
 	_, err := token.AuthKeyFromBytes(bytes)
 	assert.NoError(t, err)
 }