diff --git a/libs/pbd/pbd/abstract_ui.cc b/libs/pbd/pbd/abstract_ui.cc
index 76ad5d0da4..4c36445848 100644
--- a/libs/pbd/pbd/abstract_ui.cc
+++ b/libs/pbd/pbd/abstract_ui.cc
@@ -435,7 +435,7 @@ AbstractUI<RequestObject>::call_slot (InvalidationRecord* invalidation, const bo
 			return;
 		}
 		invalidation->ref ();
-		assert (invalidation->event_loop == this);
+		invalidation->event_loop = this;
 	}
 
 	RequestObject *req = get_request (BaseUI::CallSlot);