diff --git a/layout/forms/nsComboboxControlFrame.cpp b/layout/forms/nsComboboxControlFrame.cpp
index 0b63dee41bb1..6161004bb9ea 100644
--- a/layout/forms/nsComboboxControlFrame.cpp
+++ b/layout/forms/nsComboboxControlFrame.cpp
@@ -2540,7 +2540,7 @@ nsComboboxControlFrame::Paint(nsIPresContext*     aPresContext,
       PRBool clipEmpty;
       nsRect clipRect;
       mDisplayFrame->GetRect(clipRect);
-      aRenderingContext.SetClipRect(clipRect, nsClipCombine_kReplace, clipEmpty);
+      aRenderingContext.SetClipRect(clipRect, nsClipCombine_kIntersect, clipEmpty);
       PaintChild(aPresContext, aRenderingContext, aDirtyRect, 
                  mDisplayFrame, NS_FRAME_PAINT_LAYER_BACKGROUND);
       PaintChild(aPresContext, aRenderingContext, aDirtyRect, 
diff --git a/layout/html/forms/src/nsComboboxControlFrame.cpp b/layout/html/forms/src/nsComboboxControlFrame.cpp
index 0b63dee41bb1..6161004bb9ea 100644
--- a/layout/html/forms/src/nsComboboxControlFrame.cpp
+++ b/layout/html/forms/src/nsComboboxControlFrame.cpp
@@ -2540,7 +2540,7 @@ nsComboboxControlFrame::Paint(nsIPresContext*     aPresContext,
       PRBool clipEmpty;
       nsRect clipRect;
       mDisplayFrame->GetRect(clipRect);
-      aRenderingContext.SetClipRect(clipRect, nsClipCombine_kReplace, clipEmpty);
+      aRenderingContext.SetClipRect(clipRect, nsClipCombine_kIntersect, clipEmpty);
       PaintChild(aPresContext, aRenderingContext, aDirtyRect, 
                  mDisplayFrame, NS_FRAME_PAINT_LAYER_BACKGROUND);
       PaintChild(aPresContext, aRenderingContext, aDirtyRect,