--- a/layout/painting/nsDisplayList.cpp
+++ b/layout/painting/nsDisplayList.cpp
@@ -8524,19 +8524,21 @@ nsDisplayMask::PaintAsLayer(nsDisplayLis
                                                   mFrame,  mVisibleRect,
                                                   borderArea, aBuilder,
                                                   aManager,
                                                   mHandleOpacity, flags);
 
   // Clip the drawing target by mVisibleRect, which contains the visible
   // region of the target frame and its out-of-flow and inflow descendants.
   gfxContext* context = aCtx->ThebesContext();
-  context->Clip(NSRectToSnappedRect(mVisibleRect,
-                                    mFrame->PresContext()->AppUnitsPerDevPixel(),
-                                    *aCtx->GetDrawTarget()));
+
+  Rect bounds =
+    NSRectToRect(mVisibleRect, mFrame->PresContext()->AppUnitsPerDevPixel());
+  bounds.RoundOut();
+  context->Clip(bounds);
 
   ComputeMaskGeometry(params);
 
   image::DrawResult result =
     nsSVGIntegrationUtils::PaintMaskAndClipPath(params);
 
   context->PopClip();