diff --git a/entityreference.module b/entityreference.module
index bdcb562..da3c60a 100644
--- a/entityreference.module
+++ b/entityreference.module
@@ -170,6 +170,7 @@ function _entityreference_get_behavior_handler($behavior) {
   $object_cache = drupal_static(__FUNCTION__);
 
   if (!isset($object_cache[$behavior])) {
+    module_load_include('module', 'ctools');
     ctools_include('plugins');
     $class = ctools_plugin_load_class('entityreference', 'behavior', $behavior, 'class');