diff --git a/plugins/views_plugin_style.inc b/plugins/views_plugin_style.inc
index ed5d3c02..6d404736 100644
--- a/plugins/views_plugin_style.inc
+++ b/plugins/views_plugin_style.inc
@@ -481,7 +481,7 @@ class views_plugin_style extends views_plugin {
             if ($rendered) {
               $grouping = $group_content;
               if ($rendered_strip) {
-                $group_content = $grouping = strip_tags(htmlspecialchars_decode($group_content));
+                $group_content = $grouping = strip_tags(htmlspecialchars_decode((string) $group_content));
               }
             }
             else {