diff --git a/tests/lib/contacts/localadressbook.php b/tests/lib/contacts/localadressbook.php
index 5fa260ffc3..a34d45bf3d 100644
--- a/tests/lib/contacts/localadressbook.php
+++ b/tests/lib/contacts/localadressbook.php
@@ -78,6 +78,9 @@ class SimpleUserForTesting implements \OCP\IUser {
 	public function getHome() {
 	}
 
+	public function getBackendClassName() {
+	}
+
 	public function canChangeAvatar() {
 	}