diff --git a/webhook_test.go b/webhook_test.go
index d99b0b8..9ec5076 100755
--- a/webhook_test.go
+++ b/webhook_test.go
@@ -355,7 +355,7 @@ func startWebhookServer(t *testing.T, webhookBin, configPath string, extraArgs .
 		t.Fatalf("failed to start webhook: %s", err)
 	}
 
-	waitForServerReady(t, ip, port)
+	waitForServerReady(t, net.JoinHostPort(ip, port), &http.Client{})
 
 	return cmd, logs, "http://" + net.JoinHostPort(ip, port)
 }