--- /dev/null
+--- 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;
+ }