--- a/layout/generic/nsGfxScrollFrame.cpp
+++ b/layout/generic/nsGfxScrollFrame.cpp
@@ -2190,18 +2190,23 @@ nsGfxScrollFrameInner::BuildDisplayList(
   // Not all our descendants will be clipped by overflow clipping, but all
   // the ones that aren't clipped will be out of flow frames that have already
   // had dirty rects saved for them by their parent frames calling
   // MarkOutOfFlowChildrenForDisplayList, so it's safe to restrict our
   // dirty rect here.
   dirtyRect.IntersectRect(aDirtyRect, mScrollPort);
 
   // Override the dirty rectangle if the displayport has been set.
+  nsRect displayPort;
   bool usingDisplayport =
-    nsLayoutUtils::GetDisplayPort(mOuter->GetContent(), &dirtyRect);
+    nsLayoutUtils::GetDisplayPort(mOuter->GetContent(), &displayPort) &&
+    !aBuilder->IsForEventDelivery();
+  if (usingDisplayport) {
+    dirtyRect = displayPort;
+  }
 
   nsDisplayListCollection set;
   rv = mOuter->BuildDisplayListForChild(aBuilder, mScrolledFrame, dirtyRect, set);
   NS_ENSURE_SUCCESS(rv, rv);
 
   // Since making new layers is expensive, only use nsDisplayScrollLayer
   // if the area is scrollable and there's a displayport (or we're the content
   // process).