diff --git a/components/script/dom/document.rs b/components/script/dom/document.rs
index d568a21d985..029b8b8aa27 100644
--- a/components/script/dom/document.rs
+++ b/components/script/dom/document.rs
@@ -2403,9 +2403,10 @@ impl Document {
 
         // Update the counter of spurious animation frames.
         let spurious_frames = self.spurious_animation_frames.get();
-        if callbacks_did_not_trigger_reflow && spurious_frames < SPURIOUS_ANIMATION_FRAME_THRESHOLD
-        {
-            self.spurious_animation_frames.set(spurious_frames + 1);
+        if callbacks_did_not_trigger_reflow {
+            if spurious_frames < SPURIOUS_ANIMATION_FRAME_THRESHOLD {
+                self.spurious_animation_frames.set(spurious_frames + 1);
+            }
         } else {
             self.spurious_animation_frames.set(0);
         }
diff --git a/tests/wpt/meta/MANIFEST.json b/tests/wpt/meta/MANIFEST.json
index bc23e2e5dad..466711e22c8 100644
--- a/tests/wpt/meta/MANIFEST.json
+++ b/tests/wpt/meta/MANIFEST.json
@@ -729603,7 +729603,7 @@
        ]
       ],
       "spurious-frame-callbacks-optimization.html": [
-       "b4c582cd5edce8f92a2da0b44131a8dbdff60f11",
+       "82fbe12db546dd52e2e17d55fd5286b55ca2e7fe",
        [
         null,
         {}
diff --git a/tests/wpt/tests/html/webappapis/animation-frames/spurious-frame-callbacks-optimization.html b/tests/wpt/tests/html/webappapis/animation-frames/spurious-frame-callbacks-optimization.html
index b4c582cd5ed..82fbe12db54 100644
--- a/tests/wpt/tests/html/webappapis/animation-frames/spurious-frame-callbacks-optimization.html
+++ b/tests/wpt/tests/html/webappapis/animation-frames/spurious-frame-callbacks-optimization.html
@@ -10,30 +10,30 @@
 </body>
 <script>
 "use strict";
-let frame = 0;
-const draw = (t) => {
-  frame += 1;
-  if (frame < 11) {
-    // Don't mutate the DOM for 10 frames to meet the threshold for Servo's
-    // spurious frame optimization to kick in.
-    requestAnimationFrame(draw);
-  } else if (frame == 11) {
-    // Don't schedule next rAF so the compositor's tick is disabled.
-    // This is specific to Servo as the spurious frame detection at the
-    // time of this test was broken.
-    setTimeout(() => {
-      requestAnimationFrame(draw);
-    }, 10);
-  } else {
-    // Normal frames.
-    document.getElementById('target').innerText = t;
-    requestAnimationFrame(draw);
-  }
-};
-
 async_test(function(test) {
+  let frame = 0;
+  const draw = (t) => {
+    frame += 1;
+    if (frame < 11) {
+      // Don't mutate the DOM for 10 frames to meet the threshold for Servo's
+      // spurious frame optimization to kick in.
+      requestAnimationFrame(draw);
+    } else if (frame == 11) {
+      // Don't schedule next rAF so the compositor's tick is disabled.
+      // This is specific to Servo as the spurious frame detection at the
+      // time of this test was broken.
+      test.step_timeout(() => {
+        requestAnimationFrame(draw);
+      }, 0);
+    } else {
+      // Normal frames.
+      document.getElementById('target').innerText = t;
+      requestAnimationFrame(draw);
+    }
+  };
+
   let target = document.getElementById('target');
-  setTimeout(test.step_func_done(() => {
+  test.step_timeout(test.step_func_done(() => {
     assert_greater_than(parseInt(target.innerText), 500);
   }), 550);
   requestAnimationFrame(draw);