diff --git a/src/__celerity_resource_map__.php b/src/__celerity_resource_map__.php
index 125e50a785..f8a8050735 100644
--- a/src/__celerity_resource_map__.php
+++ b/src/__celerity_resource_map__.php
@@ -1186,7 +1186,7 @@ celerity_register_resource_map(array(
   ),
   'javelin-behavior-differential-toggle-files' =>
   array(
-    'uri' => '/res/fb94e3f5/rsrc/js/application/differential/behavior-toggle-files.js',
+    'uri' => '/res/983960b4/rsrc/js/application/differential/behavior-toggle-files.js',
     'type' => 'js',
     'requires' =>
     array(
diff --git a/webroot/rsrc/js/application/differential/behavior-toggle-files.js b/webroot/rsrc/js/application/differential/behavior-toggle-files.js
index dff42a936d..60f7e50274 100644
--- a/webroot/rsrc/js/application/differential/behavior-toggle-files.js
+++ b/webroot/rsrc/js/application/differential/behavior-toggle-files.js
@@ -59,7 +59,7 @@ JX.behavior('differential-toggle-files', function(config) {
     function(e) {
       var link = e.getNode('tag:a');
       var id = link.getAttribute('href');
-      if (!id.match(/^#.+/)) {
+      if (!id || !id.match(/^#.+/)) {
         return;
       }
       // The target may have either a matching name or a matching id.