--- a/src/xfce-appfinder-window.c
+++ b/src/xfce-appfinder-window.c
@@ -1208,7 +1208,8 @@ _xfce_appfinder_window_visible_func (GtkTreeModel *filter,
 
   g_free (search_text);
   g_free (text);
-  g_free (category);
+  if (category)
+    g_free (category);
 
   return visible;
 }