diff --git a/gtk2_ardour/plugin_ui.cc b/gtk2_ardour/plugin_ui.cc
index 011151e29b..93da6e8df8 100644
--- a/gtk2_ardour/plugin_ui.cc
+++ b/gtk2_ardour/plugin_ui.cc
@@ -429,12 +429,12 @@ PluginUIWindow::on_key_release_event (GdkEventKey *event)
 			if (_pluginui->non_gtk_gui()) {
 				_pluginui->forward_key_event (event);
 			}
-			return true;
 		}
-		return false;
 	} else {
-		return true;
+		gtk_window_propagate_key_event (GTK_WINDOW(gobj()), event);
 	}
+	/* don't forward releases */
+	return true;
 }
 
 void