diff --git a/plugins/entity/PanelizerEntityDefault.class.php b/plugins/entity/PanelizerEntityDefault.class.php
index 653cea2..3c020cf 100644
--- a/plugins/entity/PanelizerEntityDefault.class.php
+++ b/plugins/entity/PanelizerEntityDefault.class.php
@@ -2723,7 +2723,6 @@ abstract class PanelizerEntityDefault implements PanelizerEntityInterface {
     $info['classes_array'] = array();
 
     if (!empty($panelizer->css_class)) {
-      ctools_include('cleanstring');
       foreach (explode(' ', $panelizer->css_class) as $class) {
         $class = ctools_context_keyword_substitute($class, array(), $display->context);
         if ($class) {