--- a/widget/tests/test_bug596600.xul
+++ b/widget/tests/test_bug596600.xul
@@ -144,21 +144,18 @@ function test2() {
         ok(!gIFrame.matches(":hover"), "iframe shouldn't be hovered");
         ok(!box.matches(":hover"), "Box shouldn't be hovered");
         // Re-activate it.
         changeFocusAndAwaitSyntheticMouse(function () {
           ok(gIFrame.matches(":hover"), "iframe should be hovered");
           ok(box.matches(":hover"), "Box should be hovered");
           // Unhover box and iframe by moving the mouse outside the window.
           moveMouseTo(0, 150, function () {
-            const isOSXSnowLeopard = navigator.userAgent.indexOf("Mac OS X 10.6") != -1;
-            if (!isOSXSnowLeopard) {
-              ok(!gIFrame.matches(":hover"), "iframe shouldn't be hovered");
-              ok(!box.matches(":hover"), "box shouldn't be hovered");
-            }
+            ok(!gIFrame.matches(":hover"), "iframe shouldn't be hovered");
+            ok(!box.matches(":hover"), "box shouldn't be hovered");
             finalize();
           });
         }, gLeftWindow, box);
       }, gRightWindow, box);
     }, gLeftWindow, box);
   });
 }