diff --git a/Formula/tunnel.rb b/Formula/tunnel.rb
index 9d703b09f772..af4d815d3bdd 100644
--- a/Formula/tunnel.rb
+++ b/Formula/tunnel.rb
@@ -22,6 +22,6 @@ def install
   end
 
   test do
-    system bin/"tunnel", "ping"
+    assert_match "you need an api key", shell_output(bin/"tunnel 8080", 1)
   end
 end