--- a/gfx/layers/apz/src/APZCTreeManager.cpp
+++ b/gfx/layers/apz/src/APZCTreeManager.cpp
@@ -1788,21 +1788,30 @@ APZCTreeManager::GetAPZCAtPoint(HitTesti
           return TraversalFlag::Abort;
         }
         return TraversalFlag::Continue;
       }
   );
 
   if (*aOutHitResult != HitNothing) {
       MOZ_ASSERT(resultNode);
-      if (aOutHitScrollbar) {
-        for (HitTestingTreeNode* n = resultNode; n; n = n->GetParent()) {
-          if (n->IsScrollbarNode()) {
+      for (HitTestingTreeNode* n = resultNode; n; n = n->GetParent()) {
+        if (n->IsScrollbarNode()) {
+          if (aOutHitScrollbar) {
             *aOutHitScrollbar = true;
           }
+          // If we hit a scrollbar, target the APZC for the content scrolled
+          // by the scrollbar. (The scrollbar itself doesn't scroll with the
+          // scrolled content, so it doesn't carry the scrolled content's
+          // scroll metadata).
+          ScrollableLayerGuid guid(n->GetLayersId(), 0, n->GetScrollTargetId());
+          if (RefPtr<HitTestingTreeNode> scrollTarget = GetTargetNode(guid, &GuidComparatorIgnoringPresShell)) {
+            MOZ_ASSERT(scrollTarget->GetApzc());
+            return scrollTarget->GetApzc();
+          }
         }
       }
 
       AsyncPanZoomController* result = GetTargetApzcForNode(resultNode);
       if (!result) {
         result = FindRootApzcForLayersId(resultNode->GetLayersId());
         MOZ_ASSERT(result);
         APZCTM_LOG("Found target %p using root lookup\n", result);

--- a/gfx/layers/apz/src/HitTestingTreeNode.cpp
+++ b/gfx/layers/apz/src/HitTestingTreeNode.cpp
@@ -123,16 +123,22 @@ HitTestingTreeNode::GetScrollThumbLength
 }
 
 bool
 HitTestingTreeNode::IsScrollbarNode() const
 {
   return mIsScrollbarContainer || (mScrollDir != ScrollDirection::NONE);
 }
 
+FrameMetrics::ViewID
+HitTestingTreeNode::GetScrollTargetId() const
+{
+  return mScrollViewId;
+}
+
 void
 HitTestingTreeNode::SetFixedPosData(FrameMetrics::ViewID aFixedPosTarget)
 {
   mFixedPosTarget = aFixedPosTarget;
 }
 
 FrameMetrics::ViewID
 HitTestingTreeNode::GetFixedPosTarget() const

--- a/gfx/layers/apz/src/HitTestingTreeNode.h
+++ b/gfx/layers/apz/src/HitTestingTreeNode.h
@@ -93,16 +93,17 @@ public:
 
   void SetScrollbarData(FrameMetrics::ViewID aScrollViewId,
                         ScrollDirection aDir,
                         int32_t aScrollThumbLength,
                         bool aIsScrollContainer);
   bool MatchesScrollDragMetrics(const AsyncDragMetrics& aDragMetrics) const;
   LayerIntCoord GetScrollThumbLength() const;
   bool IsScrollbarNode() const;
+  FrameMetrics::ViewID GetScrollTargetId() const;
 
   /* Fixed pos info */
 
   void SetFixedPosData(FrameMetrics::ViewID aFixedPosTarget);
   FrameMetrics::ViewID GetFixedPosTarget() const;
 
   /* Convert aPoint into the LayerPixel space for the layer corresponding to
    * this node. */