diff --git a/panels.module.orig b/panels.module
index d24b9bc..87ec704 100644
--- a/panels.module.orig
+++ b/panels.module
@@ -1124,7 +1124,7 @@ function panels_get_current_page_display($change = NULL) {
 /**
  * Clean up the panel pane variables for the template.
  */
-function template_preprocess_panels_pane($vars) {
+function template_preprocess_panels_pane(&$vars) {
   $content = $vars['output'];
   // basic classes
   $vars['classes'] = 'panel-pane';