diff --git a/src/proxy-animation.js b/src/proxy-animation.js
index 417d9e5..c7bcc9f 100644
--- a/src/proxy-animation.js
+++ b/src/proxy-animation.js
@@ -921,7 +921,9 @@ function autoAlignStartTime(details) {
   // TODO: Clarify how range duration should be resolved
   details.rangeDuration = endOffset.value - startOffset.value;
   // 7. Set start time to start offset if effective playback rate ≥ 0, and end offset otherwise.
-  const playbackRate = effectivePlaybackRate(details);
+  // Not by spec: Applying the pending playback rate. If not, the start time will be re-aligned in `commitPendingPlay()`
+  applyPendingPlaybackRate(details);
+  const playbackRate = details.animation.playbackRate;
   details.startTime = fromCssNumberish(details,playbackRate >= 0 ? startOffset : endOffset);
 
   // 8. Clear hold time.
diff --git a/test/expected.txt b/test/expected.txt
index 84d7f50..cf676bc 100644
--- a/test/expected.txt
+++ b/test/expected.txt
@@ -838,12 +838,12 @@ PASS	/scroll-animations/scroll-timelines/play-animation.html	The ready promise s
 PASS	/scroll-animations/scroll-timelines/play-animation.html	A pending ready promise should be resolved and not replaced when the animation enters the running state
 PASS	/scroll-animations/scroll-timelines/play-animation.html	Resuming an animation from paused realigns with scroll position.
 PASS	/scroll-animations/scroll-timelines/play-animation.html	If a pause operation is interrupted, the ready promise is reused
-FAIL	/scroll-animations/scroll-timelines/play-animation.html	A pending playback rate is used when determining timeline range alignment
+PASS	/scroll-animations/scroll-timelines/play-animation.html	A pending playback rate is used when determining timeline range alignment
 PASS	/scroll-animations/scroll-timelines/play-animation.html	Playing a canceled animation sets the start time
 PASS	/scroll-animations/scroll-timelines/play-animation.html	Playing a canceled animation backwards sets the start time
 PASS	/scroll-animations/scroll-timelines/reverse-animation.html	Setting current time while reverse-pending preserves currentTime
 PASS	/scroll-animations/scroll-timelines/reverse-animation.html	Reversing an animation inverts the playback rate
-FAIL	/scroll-animations/scroll-timelines/reverse-animation.html	Reversing an animation resets a sticky start time.
+PASS	/scroll-animations/scroll-timelines/reverse-animation.html	Reversing an animation resets a sticky start time.
 PASS	/scroll-animations/scroll-timelines/reverse-animation.html	Reversing an animation does not cause it to leave the pending state
 PASS	/scroll-animations/scroll-timelines/reverse-animation.html	Reversing an animation does not cause it to resolve the ready promise
 PASS	/scroll-animations/scroll-timelines/reverse-animation.html	Reversing an animation with a negative playback rate should cause the animation to play in a forward direction