diff --git a/src/testing/example.go b/src/testing/example.go
index f5762e4db4a..61339a6465f 100644
--- a/src/testing/example.go
+++ b/src/testing/example.go
@@ -56,8 +56,8 @@ func runExample(eg InternalExample) (ok bool) {
 	os.Stdout = w
 	outC := make(chan string)
 	go func() {
-		buf := new(bytes.Buffer)
-		_, err := io.Copy(buf, r)
+		var buf bytes.Buffer
+		_, err := io.Copy(&buf, r)
 		r.Close()
 		if err != nil {
 			fmt.Fprintf(os.Stderr, "testing: copying pipe: %v\n", err)