--- a/layout/painting/nsDisplayList.cpp
+++ b/layout/painting/nsDisplayList.cpp
@@ -6183,31 +6183,37 @@ nsDisplayTransform::ShouldPrerenderTrans
     EffectCompositor::SetPerformanceWarning(
       aFrame, eCSSProperty_transform,
       AnimationPerformanceWarning(
         AnimationPerformanceWarning::Type::TransformFrameInactive));
 
     return NoPrerender;
   }
 
+  // If the incoming dirty rect already contains the entire overflow area,
+  // we are already rendering the entire content.
+  nsRect overflow = aFrame->GetVisualOverflowRectRelativeToSelf();
+  if (aDirtyRect->Contains(overflow)) {
+    return FullPrerender;
+  }
+
   float viewportRatioX = gfxPrefs::AnimationPrerenderViewportRatioLimitX();
   float viewportRatioY = gfxPrefs::AnimationPrerenderViewportRatioLimitY();
   uint32_t absoluteLimitX = gfxPrefs::AnimationPrerenderAbsoluteLimitX();
   uint32_t absoluteLimitY = gfxPrefs::AnimationPrerenderAbsoluteLimitY();
   nsSize refSize = aBuilder->RootReferenceFrame()->GetSize();
   // Only prerender if the transformed frame's size is <= a multiple of the
   // reference frame size (~viewport), and less than an absolute limit.
   // Both the ratio and the absolute limit are configurable.
   nsSize relativeLimit(nscoord(refSize.width * viewportRatioX),
                        nscoord(refSize.height * viewportRatioY));
   nsSize absoluteLimit(aFrame->PresContext()->DevPixelsToAppUnits(absoluteLimitX),
                        aFrame->PresContext()->DevPixelsToAppUnits(absoluteLimitY));
   nsSize maxSize = Min(relativeLimit, absoluteLimit);
   gfxSize scale = nsLayoutUtils::GetTransformToAncestorScale(aFrame);
-  nsRect overflow = aFrame->GetVisualOverflowRectRelativeToSelf();
   nsSize frameSize = nsSize(overflow.Size().width * scale.width,
                             overflow.Size().height * scale.height);
   if (frameSize <= maxSize) {
     *aDirtyRect = overflow;
     return FullPrerender;
   } else if (gfxPrefs::PartiallyPrerenderAnimatedContent()) {
     *aDirtyRect = ComputePartialPrerenderArea(*aDirtyRect, overflow, maxSize);
     return PartialPrerender;