diff --git a/includes/menu.inc b/includes/menu.inc
index d5707b027e85911a0e248a82eed76060c69a312e..95ec71e595067d82be699314762ecb824bfa9627 100644
--- a/includes/menu.inc
+++ b/includes/menu.inc
@@ -1211,6 +1211,10 @@ function drupal_help_arg($arg = array()) {
 function menu_get_active_help() {
   $output = '';
   $router_path = menu_tab_root_path();
+  // We will always have a path unless we are on a 403 or 404.
+  if (!$router_path) {
+    return '';
+  }
 
   $arg = drupal_help_arg(arg(NULL));
   $empty_arg = drupal_help_arg();