diff --git a/lib/app.php b/lib/app.php
index d1018c37aa74c1fdf40c4e9889d77cd4c526da27..2e9ec4d63086ab411d6ac795b32536fdae478b20 100755
--- a/lib/app.php
+++ b/lib/app.php
@@ -394,7 +394,7 @@ class OC_App{
 			return trim($version);
 		}else{
 			$appData=self::getAppInfo($appid);
-			return $appData['version'];
+			return isset($appData['version'])? $appData['version'] : '';
 		}
 	}