diff --git a/lib/autoloader.php b/lib/autoloader.php
index 3228ca29b2288ca768cd5c1412e9bdfc6f6bc88b..3451f799e18eb1b2e0dff099d360e7c516fcadef 100644
--- a/lib/autoloader.php
+++ b/lib/autoloader.php
@@ -150,7 +150,7 @@ class Autoloader {
 	 * @brief Sets the optional low-latency cache for class to path mapping.
 	 * @param \OC\Memcache\Cache $memoryCache Instance of memory cache.
 	 */
-	public function setMemoryCache(\OC\Memcache\Cache $memoryCache) {
+	public function setMemoryCache(\OC\Memcache\Cache $memoryCache = null) {
 		$this->memoryCache = $memoryCache;
 	}
 }