--- a/gfx/layers/apz/src/AsyncPanZoomController.cpp
+++ b/gfx/layers/apz/src/AsyncPanZoomController.cpp
@@ -1657,16 +1657,20 @@ nsEventStatus AsyncPanZoomController::On
 
 nsEventStatus AsyncPanZoomController::OnLongPress(const TapGestureInput& aEvent) {
   APZC_LOG("%p got a long-press in state %d\n", this, mState);
   nsRefPtr<GeckoContentController> controller = GetGeckoContentController();
   if (controller) {
     int32_t modifiers = WidgetModifiersToDOMModifiers(aEvent.modifiers);
     CSSPoint geckoScreenPoint;
     if (ConvertToGecko(aEvent.mLocalPoint, &geckoScreenPoint)) {
+      if (CurrentTouchBlock()->IsDuringFastMotion()) {
+        APZC_LOG("%p dropping long-press because of fast motion\n", this);
+        return nsEventStatus_eIgnore;
+      }
       uint64_t blockId = GetInputQueue()->InjectNewTouchBlock(this);
       controller->HandleLongTap(geckoScreenPoint, modifiers, GetGuid(), blockId);
       return nsEventStatus_eConsumeNoDefault;
     }
   }
   return nsEventStatus_eIgnore;
 }
 

--- a/gfx/layers/apz/src/InputQueue.cpp
+++ b/gfx/layers/apz/src/InputQueue.cpp
@@ -105,16 +105,17 @@ InputQueue::ReceiveTouchInput(const nsRe
   nsRefPtr<AsyncPanZoomController> target = block->GetTargetApzc();
 
   nsEventStatus result = nsEventStatus_eIgnore;
 
   // XXX calling ArePointerEventsConsumable on |target| may be wrong here if
   // the target isn't confirmed and the real target turns out to be something
   // else. For now assume this is rare enough that it's not an issue.
   if (block->IsDuringFastMotion()) {
+    INPQ_LOG("dropping event due to block %p being in fast motion\n", block);
     result = nsEventStatus_eConsumeNoDefault;
   } else if (target && target->ArePointerEventsConsumable(block, aEvent.AsMultiTouchInput().mTouches.Length())) {
     result = nsEventStatus_eConsumeDoDefault;
   }
   if (!MaybeHandleCurrentBlock(target, block, aEvent)) {
     block->AddEvent(aEvent.AsMultiTouchInput());
   }
   return result;
@@ -219,18 +220,18 @@ InputQueue::MaybeRequestContentResponse(
 }
 
 uint64_t
 InputQueue::InjectNewTouchBlock(AsyncPanZoomController* aTarget)
 {
   TouchBlockState* block = StartNewTouchBlock(aTarget,
     /* aTargetConfirmed = */ true,
     /* aCopyAllowedTouchBehaviorFromCurrent = */ true);
-  INPQ_LOG("%p injecting new touch block with id %" PRIu64 " and target %p\n",
-    this, block->GetBlockId(), aTarget);
+  INPQ_LOG("injecting new touch block %p with id %" PRIu64 " and target %p\n",
+    block, block->GetBlockId(), aTarget);
   ScheduleMainThreadTimeout(aTarget, block->GetBlockId());
   return block->GetBlockId();
 }
 
 void
 InputQueue::SweepDepletedBlocks()
 {
   // We're going to start a new block, so clear out any depleted blocks at the head of the queue.