diff --git a/src/net/http/httputil/reverseproxy_test.go b/src/net/http/httputil/reverseproxy_test.go
index 8e181dbb042..8ab57b4cbb0 100644
--- a/src/net/http/httputil/reverseproxy_test.go
+++ b/src/net/http/httputil/reverseproxy_test.go
@@ -342,7 +342,7 @@ func TestReverseProxyCancelation(t *testing.T) {
 	}()
 	res, err := http.DefaultClient.Do(getReq)
 	if res != nil {
-		t.Error("got response %v; want nil", res.Status)
+		t.Errorf("got response %v; want nil", res.Status)
 	}
 	if err == nil {
 		// This should be an error like: