--- a/devtools/client/responsivedesign/test/head.js
+++ b/devtools/client/responsivedesign/test/head.js
@@ -39,17 +39,17 @@ var openRDM = Task.async(function* (tab 
                                    method = "menu") {
   let manager = ResponsiveUIManager;
 
   let opened = once(manager, "on");
   let resized = once(manager, "content-resize");
   if (method == "menu") {
     document.getElementById("menu_responsiveUI").doCommand();
   } else {
-    synthesizeKeyFromKeyTag(document.getElementById("key_responsiveUI"));
+    synthesizeKeyFromKeyTag(document.getElementById("key_responsiveDesignMode"));
   }
   yield opened;
 
   let rdm = manager.getResponsiveUIForTab(tab);
   rdm.transitionsEnabled = false;
   registerCleanupFunction(() => {
     rdm.transitionsEnabled = true;
   });