diff --git a/lib/Hooks/UserHooks.php b/lib/Hooks/UserHooks.php
index 24739f63..5846b7b2 100644
--- a/lib/Hooks/UserHooks.php
+++ b/lib/Hooks/UserHooks.php
@@ -198,8 +198,16 @@ public function postCreateUser($params) {
 	public function postDeleteUser($params) {
 
 		if (App::isEnabled('encryption')) {
-			$this->keyManager->deletePublicKey($params['uid']);
+			/**
+			 * Adding a safe condition to make sure the uid is not
+			 * empty or null.
+			 */
+			if (!is_null($params['uid']) && ($params['uid'] !== '')) {
+				$this->keyManager->deletePublicKey($params['uid']);
+				\OC::$server->getEncryptionKeyStorage()->deleteAltUserStorageKeys($params['uid']);
+			}
 		}
+
 	}
 
 	/**