diff --git a/editor/libeditor/EditorEventListener.cpp b/editor/libeditor/EditorEventListener.cpp
index cba58ed7bc..a1c8058752 100644
--- a/editor/libeditor/EditorEventListener.cpp
+++ b/editor/libeditor/EditorEventListener.cpp
@@ -458,7 +458,7 @@ EditorEventListener::HandleEvent(nsIDOMEvent* aEvent)
       if (widgetMouseEvent->button != WidgetMouseEvent::eLeftButton) {
         return NS_OK;
       }
-      [[fallthrough]];
+      MOZ_FALLTHROUGH;
     }
     // auxclick
     case eMouseAuxClick: {