diff --git a/plugins/display_renderers/panels_renderer_legacy.class.php b/plugins/display_renderers/panels_renderer_legacy.class.php
index 42fb01c..4d8a787 100644
--- a/plugins/display_renderers/panels_renderer_legacy.class.php
+++ b/plugins/display_renderers/panels_renderer_legacy.class.php
@@ -239,7 +239,7 @@ class panels_renderer_legacy {
     }
 
     // Pass long the css_class that is usually available.
-    if (!empty($pane->css['css_class'])) {
+    if (!empty($pane->css['css_class']) && is_object($content)) {
       $content->css_class = $pane->css['css_class'];
     }