diff --git a/apps/dav/lib/caldav/birthdayservice.php b/apps/dav/lib/caldav/birthdayservice.php
index 1d0b06f03a813f2bda3e3d15e0c6c4b280f9d897..b74116f40831f3be307c02653874df01bc516924 100644
--- a/apps/dav/lib/caldav/birthdayservice.php
+++ b/apps/dav/lib/caldav/birthdayservice.php
@@ -204,7 +204,7 @@ class BirthdayService {
 	}
 
 	/**
-	 * @param $addressBookId
+	 * @param integer $addressBookId
 	 * @return mixed
 	 */
 	protected function getAllAffectedPrincipals($addressBookId) {