diff --git a/core/ajax/translations.php b/core/ajax/translations.php
index e52a2e9b1e8292b8d90295b77858ddc465c9261f..c9c642077982b0671a39ba156f932e1176248b3c 100644
--- a/core/ajax/translations.php
+++ b/core/ajax/translations.php
@@ -21,7 +21,8 @@
 *
 */
 
-$app = $_POST["app"];
+$app = isset($_POST["app"]) ? $_POST["app"] : "";
+
 $app = OC_App::cleanAppId($app);
 
 $l = OC_L10N::get( $app );