diff --git a/layout/base/nsDisplayList.cpp b/layout/base/nsDisplayList.cpp
index bebe5c9e3e57..725ee4b0b5bd 100644
--- a/layout/base/nsDisplayList.cpp
+++ b/layout/base/nsDisplayList.cpp
@@ -3436,12 +3436,16 @@ nsDisplayLayerEventRegions::AddFrame(nsDisplayListBuilder* aBuilder,
     // are the event targets for any regions viewport frames may cover.
     return;
   }
+
   uint8_t pointerEvents = aFrame->StyleVisibility()->GetEffectivePointerEvents(aFrame);
   if (pointerEvents == NS_STYLE_POINTER_EVENTS_NONE) {
     return;
   }
-  if (!aFrame->StyleVisibility()->IsVisible()) {
-    return;
+  bool simpleRegions = aFrame->HasAnyStateBits(NS_FRAME_SIMPLE_EVENT_REGIONS);
+  if (!simpleRegions) {
+    if (!aFrame->StyleVisibility()->IsVisible()) {
+      return;
+    }
   }
   // XXX handle other pointerEvents values for SVG
 
@@ -3460,15 +3464,23 @@ nsDisplayLayerEventRegions::AddFrame(nsDisplayListBuilder* aBuilder,
   }
   borderBox += aBuilder->ToReferenceFrame(aFrame);
 
+  bool borderBoxHasRoundedCorners = false;
+  if (!simpleRegions) {
+    if (nsLayoutUtils::HasNonZeroCorner(aFrame->StyleBorder()->mBorderRadius)) {
+      borderBoxHasRoundedCorners = true;
+    } else {
+      aFrame->AddStateBits(NS_FRAME_SIMPLE_EVENT_REGIONS);
+    }
+  }
+
   const DisplayItemClip* clip = aBuilder->ClipState().GetCurrentCombinedClip(aBuilder);
-  bool borderBoxHasRoundedCorners =
-    nsLayoutUtils::HasNonZeroCorner(aFrame->StyleBorder()->mBorderRadius);
   if (clip) {
     borderBox = clip->ApplyNonRoundedIntersection(borderBox);
     if (clip->GetRoundedRectCount() > 0) {
       borderBoxHasRoundedCorners = true;
     }
   }
+
   if (borderBoxHasRoundedCorners ||
       (aFrame->GetStateBits() & NS_FRAME_SVG_LAYOUT)) {
     mMaybeHitRegion.Or(mMaybeHitRegion, borderBox);
diff --git a/layout/generic/nsFrame.cpp b/layout/generic/nsFrame.cpp
index f2cc01f400a2..9508837c8ec9 100644
--- a/layout/generic/nsFrame.cpp
+++ b/layout/generic/nsFrame.cpp
@@ -902,6 +902,8 @@ nsFrame::DidSetStyleContext(nsStyleContext* aOldStyleContext)
   if (StyleVisibility()->mDirection == NS_STYLE_DIRECTION_RTL) {
     PresContext()->SetBidiEnabled();
   }
+
+  RemoveStateBits(NS_FRAME_SIMPLE_EVENT_REGIONS);
 }
 
 // MSVC fails with link error "one or more multiply defined symbols found",
diff --git a/layout/generic/nsFrameStateBits.h b/layout/generic/nsFrameStateBits.h
index b22a3feaf2f2..0b73b453b6a9 100644
--- a/layout/generic/nsFrameStateBits.h
+++ b/layout/generic/nsFrameStateBits.h
@@ -180,6 +180,12 @@ FRAME_STATE_BIT(Generic, 33, NS_FRAME_DRAWING_AS_PAINTSERVER)
 // situation (possibly the frame itself).
 FRAME_STATE_BIT(Generic, 34, NS_FRAME_DESCENDANT_INTRINSIC_ISIZE_DEPENDS_ON_BSIZE)
 
+// A flag that tells us we can take the common path with respect to style
+// properties for this frame when building event regions. This flag is cleared
+// when any styles are changed and then we recompute it on the next build
+// of the event regions.
+FRAME_STATE_BIT(Generic, 35, NS_FRAME_SIMPLE_EVENT_REGIONS)
+
 // Frame is a display root and the retained layer tree needs to be updated
 // at the next paint via display list construction.
 // Only meaningful for display roots, so we don't really need a global state