--- a/gfx/layers/apz/test/test_layerization.html
+++ b/gfx/layers/apz/test/test_layerization.html
@@ -145,16 +145,17 @@ function startTest() {
     SimpleTest.finish();
     return;
   }
 
   driveTest();
 }
 
 SimpleTest.waitForExplicitFinish();
+SimpleTest.testInChaosMode();
 
 // Disable smooth scrolling, because it results in long-running scroll
 // animations that can result in a 'scroll' event triggered by an earlier
 // wheel event as corresponding to a later wheel event.
 // Also enable APZ test logging, since we use that data to determine whether
 // a scroll frame was layerized.
 SpecialPowers.pushPrefEnv({"set": [["general.smoothScroll", false],
                                    ["apz.test.logging_enabled", true]]},