diff --git a/lib/private/legacy/app.php b/lib/private/legacy/app.php
index a89a4650c5d335573ddb7eaeaf93752d92f6fec9..43dd3f54d84dc154b4751e85e3e5394a6559d388 100644
--- a/lib/private/legacy/app.php
+++ b/lib/private/legacy/app.php
@@ -364,6 +364,8 @@ class OC_App {
 			// check for required dependencies
 			$info = self::getAppInfo($appId);
 			self::checkAppDependencies($config, $l, $info);
+			$appPath = self::getAppPath($appId);
+			self::registerAutoloading($appId, $appPath);
 			$installer->installApp($appId);
 		}