diff --git a/js/dependent.js b/js/dependent.js
index a60fc12..0d0828a 100644
--- a/js/dependent.js
+++ b/js/dependent.js
@@ -224,6 +224,11 @@
     attach: function (context) {
       Drupal.CTools.dependent.autoAttach();
 
+      // Prevent $(...).once is not a function error.
+      if($("select.ctools-master-dependent").length === 0) {
+        return true;
+      }
+
       // Really large sets of fields are too slow with the above method, so this
       // is a sort of hacked one that's faster but much less flexible.
       $("select.ctools-master-dependent")