diff --git a/server.go b/server.go
index 8f03098..7a271b3 100644
--- a/server.go
+++ b/server.go
@@ -2,7 +2,6 @@ package main
 
 import (
 	"encoding/json"
-	"io/ioutil"
 	"log"
 	"net/http"
 	"os"
@@ -71,7 +70,7 @@ func handler(w http.ResponseWriter, req *http.Request) {
 		response.Files = make(map[string]string)
 		files := strings.Split(showFiles, ",")
 		for _, file := range files {
-			bytes, err := ioutil.ReadFile(file)
+			bytes, err := os.ReadFile(file)
 			if err != nil {
 				log.Printf("Could not read file %v: %v\n", file, err)
 				continue
diff --git a/server_test.go b/server_test.go
index 7a0e7b0..b2493e2 100644
--- a/server_test.go
+++ b/server_test.go
@@ -1,6 +1,7 @@
 package main
 
 import (
+	"bytes"
 	"encoding/json"
 	"net/http"
 	"net/http/httptest"
@@ -29,8 +30,12 @@ func TestHandler(t *testing.T) {
 		t.Errorf("handler returned wrong status code: got %v want %v", status, http.StatusOK)
 	}
 
+	result := rr.Result()
+	buf := new(bytes.Buffer)
+	buf.ReadFrom(result.Body)
+
 	var response response
-	json.Unmarshal(rr.Body.Bytes(), &response)
+	json.Unmarshal(buf.Bytes(), &response)
 
 	// test response
 	assert.Equal(t, 1, response.Counter)
@@ -43,5 +48,5 @@ func TestHandler(t *testing.T) {
 	assert.NotEmpty(t, response.Files[".gitignore"])
 
 	// test cors
-	assert.Contains(t, rr.HeaderMap["Access-Control-Allow-Origin"], "*")
+	assert.Contains(t, result.Header["Access-Control-Allow-Origin"], "*")
 }