diff --git a/simplemenu.module b/simplemenu.module
index 3e9670e..a7d665a 100644
--- a/simplemenu.module
+++ b/simplemenu.module
@@ -176,7 +176,12 @@ function _simplemenu_add_css() {
       }
       variable_set('simplemenu_css_filename', $output_filename);
     }
-    drupal_add_css($output_filename);
+    if (!module_invoke('ctools', 'api_version', '1.0')) {
+   	 return;
+ 	 } else {
+ 	 ctools_include('css');
+ 	 }
+    ctools_css_add_css($output_filename);
   }
   else {
     // in case we cannot create the dynamic CSS