diff --git a/lib/matplotlib/backends/web_backend/js/mpl.js b/lib/matplotlib/backends/web_backend/js/mpl.js
index 6f49a96f7ba..73d93d5bec9 100644
--- a/lib/matplotlib/backends/web_backend/js/mpl.js
+++ b/lib/matplotlib/backends/web_backend/js/mpl.js
@@ -89,7 +89,7 @@ mpl.figure = function(figure_id, websocket, ondownload, parent_element) {
         };
 
     this.imageObj.onunload = function() {
-        this.ws.close();
+        fig.ws.close();
     }
 
     this.ws.onmessage = this._make_on_message_function(this);