diff --git a/l10n_update.module b/l10n_update.module
index e6b2471..360dac0 100644
--- a/l10n_update.module
+++ b/l10n_update.module
@@ -87,7 +87,9 @@ function l10n_update_menu() {
  */
 function l10n_update_menu_alter(&$menu) {
   // Redirect l10n_client AJAX callback path for strings.
-  $menu['l10n_client/save']['page callback'] = 'l10n_update_client_save_string';
+  if (module_exists('l10n_client')) {
+    $menu['l10n_client/save']['page callback'] = 'l10n_update_client_save_string';
+  }
 }
 
 /**