--- a/layout/painting/nsDisplayList.h
+++ b/layout/painting/nsDisplayList.h
@@ -3842,17 +3842,18 @@ TableType GetTableTypeFromFrame(nsIFrame
  *
  * Also store ancestor frame as mStyleFrame for all rendering informations.
  */
 class nsDisplayTableBackgroundImage : public nsDisplayBackgroundImage {
 public:
   nsDisplayTableBackgroundImage(const InitData& aInitData, nsIFrame* aCellFrame);
 
   virtual uint32_t GetPerFrameKey() const override {
-    return (static_cast<uint8_t>(mTableType) << TYPE_BITS) |
+    return (mLayer << (TYPE_BITS + static_cast<uint8_t>(TableTypeBits::COUNT))) |
+           (static_cast<uint8_t>(mTableType) << TYPE_BITS) |
            nsDisplayItem::GetPerFrameKey();
   }
 
   virtual bool IsInvalid(nsRect& aRect) const override;
 
   virtual nsIFrame* FrameForInvalidation() const override { return mStyleFrame; }
 
   NS_DISPLAY_DECL_NAME("TableBackgroundImage", TYPE_TABLE_BACKGROUND_IMAGE)