--- a/dom/tests/mochitest/bugs/test_resize_move_windows.html
+++ b/dom/tests/mochitest/bugs/test_resize_move_windows.html
@@ -257,20 +257,22 @@ function checkChangeIsEnabled(aWindow, a
   });
   });
   });
   });
   });
   });
 }
 
+SpecialPowers.pushPrefEnv({"set": [["dom.disable_window_move_resize", false]]}, function() {
 SimpleTest.waitForFocus(function() {
   if (screen.width <= 200 || screen.height <= 200) {
-    todo(false, "The screen is too small to run this test.");
+    todo(false, "The screen needs to be bigger than 200px*200px to run this test.");
     SimpleTest.finish();
+    return;
   }
 
   backValues();
 
   // The current window can't change it's own size and position.
   checkChangeIsDisabled(window, function() {
     // We create a window and check that it can change its own size and position.
     // However, passing size/position parameters to window.open should work.
@@ -313,13 +315,14 @@ SimpleTest.waitForFocus(function() {
               });
             });
           }, w, false);
         });
       })
     }, w, false);
   });
 });
+}); // SpecialPowers.pushPrefEnv()
 
 </script>
 </pre>
 </body>
 </html>