diff --git a/boards/static/js/form.js b/boards/static/js/form.js
--- a/boards/static/js/form.js
+++ b/boards/static/js/form.js
@@ -96,6 +96,9 @@ function selectFileChoice() {
             form.submit();
             $('.post-form-w').unblock();
         };
+        worker.port.onerror = function(event){
+                throw new Error(event.message + " (" + event.filename + ":" + event.lineno + ")");
+        };
         worker.port.start();
 
         var form = $('#form');
diff --git a/boards/static/js/main.js b/boards/static/js/main.js
--- a/boards/static/js/main.js
+++ b/boards/static/js/main.js
@@ -88,6 +88,9 @@ function initFavPanel() {
         worker.port.onmessage = function(e) {
             updateFavPosts(e.data);
         };
+        worker.port.onerror = function(event){
+                throw new Error(event.message + " (" + event.filename + ":" + event.lineno + ")");
+        };
         worker.port.start();
 
         $(favPanelButton).click(function() {