diff --git a/gfx/2d/Matrix.h b/gfx/2d/Matrix.h
index c9e8ef67b2ee..632b7583ae26 100644
--- a/gfx/2d/Matrix.h
+++ b/gfx/2d/Matrix.h
@@ -1907,7 +1907,9 @@ public:
                                                    const RectTyped<TargetUnits, F>& aClip) const
   {
     if (mType == MatrixType::Identity) {
-      return aRect;
+      const RectTyped<SourceUnits, F>& clipped = aRect.Intersect(aClip);
+      return RectTyped<TargetUnits, F>(clipped.X(), clipped.Y(),
+                                       clipped.Width(), clipped.Height());
     }
 
     if (mType == MatrixType::Simple) {