--- a/layout/base/FrameLayerBuilder.cpp
+++ b/layout/base/FrameLayerBuilder.cpp
@@ -1402,17 +1402,17 @@ ContainerState::CreateOrRecycleThebesLay
   gfxMatrix matrix;
   matrix.Translate(gfxPoint(pixOffset.x, pixOffset.y));
   layer->SetBaseTransform(gfx3DMatrix::From2D(matrix));
 
   // FIXME: Temporary workaround for bug 681192 and bug 724786.
 #ifndef MOZ_ANDROID_OMTC
   // Calculate exact position of the top-left of the active scrolled root.
   // This might not be 0,0 due to the snapping in ScaleToNearestPixels.
-  gfxPoint activeScrolledRootTopLeft = scaledOffset - matrix.GetTranslation();
+  gfxPoint activeScrolledRootTopLeft = scaledOffset - matrix.GetTranslation() + mParameters.mOffset;
   // If it has changed, then we need to invalidate the entire layer since the
   // pixels in the layer buffer have the content at a (subpixel) offset
   // from what we need.
   if (!activeScrolledRootTopLeft.WithinEpsilonOf(data->mActiveScrolledRootPosition, SUBPIXEL_OFFSET_EPSILON)) {
     data->mActiveScrolledRootPosition = activeScrolledRootTopLeft;
     InvalidateEntireThebesLayer(layer, aActiveScrolledRoot);
   } else if (didResetScrollPositionForLayerPixelAlignment) {
     data->mActiveScrolledRootPosition = activeScrolledRootTopLeft;