diff --git a/Source/WebKit/UIProcess/RemoteLayerTree/RemoteScrollingTree.cpp b/Source/WebKit/UIProcess/RemoteLayerTree/RemoteScrollingTree.cpp
index 1a35ef10578c..94c013b6317e 100644
--- a/Source/WebKit/UIProcess/RemoteLayerTree/RemoteScrollingTree.cpp
+++ b/Source/WebKit/UIProcess/RemoteLayerTree/RemoteScrollingTree.cpp
@@ -199,7 +199,7 @@ void RemoteScrollingTree::deferWheelEventTestCompletionForReason(ScrollingNodeID
 {
     ASSERT(isMainRunLoop());
 
-    if (!m_scrollingCoordinatorProxy)
+    if (!m_scrollingCoordinatorProxy || !isMonitoringWheelEvents())
         return;
 
     m_scrollingCoordinatorProxy->deferWheelEventTestCompletionForReason(nodeID, reason);
@@ -209,7 +209,7 @@ void RemoteScrollingTree::removeWheelEventTestCompletionDeferralForReason(Scroll
 {
     ASSERT(isMainRunLoop());
 
-    if (!m_scrollingCoordinatorProxy)
+    if (!m_scrollingCoordinatorProxy || !isMonitoringWheelEvents())
         return;
 
     m_scrollingCoordinatorProxy->removeWheelEventTestCompletionDeferralForReason(nodeID, reason);
diff --git a/Source/WebKit/UIProcess/RemoteLayerTree/mac/RemoteScrollingTreeMac.mm b/Source/WebKit/UIProcess/RemoteLayerTree/mac/RemoteScrollingTreeMac.mm
index b375c871e83f..838c42e36fca 100644
--- a/Source/WebKit/UIProcess/RemoteLayerTree/mac/RemoteScrollingTreeMac.mm
+++ b/Source/WebKit/UIProcess/RemoteLayerTree/mac/RemoteScrollingTreeMac.mm
@@ -323,6 +323,9 @@
 
 void RemoteScrollingTreeMac::deferWheelEventTestCompletionForReason(ScrollingNodeID nodeID, WheelEventTestMonitor::DeferReason reason)
 {
+    if (!isMonitoringWheelEvents())
+        return;
+
     RunLoop::main().dispatch([strongThis = Ref { *this }, nodeID, reason] {
         if (auto* scrollingCoordinatorProxy = strongThis->scrollingCoordinatorProxy())
             scrollingCoordinatorProxy->deferWheelEventTestCompletionForReason(nodeID, reason);
@@ -331,6 +334,9 @@
 
 void RemoteScrollingTreeMac::removeWheelEventTestCompletionDeferralForReason(ScrollingNodeID nodeID, WheelEventTestMonitor::DeferReason reason)
 {
+    if (!isMonitoringWheelEvents())
+        return;
+
     RunLoop::main().dispatch([strongThis = Ref { *this }, nodeID, reason] {
         if (auto* scrollingCoordinatorProxy = strongThis->scrollingCoordinatorProxy())
             scrollingCoordinatorProxy->removeWheelEventTestCompletionDeferralForReason(nodeID, reason);