diff --git a/apps/user_ldap/lib/Mapping/AbstractMapping.php b/apps/user_ldap/lib/Mapping/AbstractMapping.php
index 31576c7480..47d69a9607 100644
--- a/apps/user_ldap/lib/Mapping/AbstractMapping.php
+++ b/apps/user_ldap/lib/Mapping/AbstractMapping.php
@@ -223,6 +223,8 @@ abstract class AbstractMapping {
 			$slice++;
 			$fdnsSlice = array_slice($fdns, $sliceSize * ($slice - 1), $sliceSize);
 
+			/** @see https://github.com/vimeo/psalm/issues/4995 */
+			/** @psalm-suppress TypeDoesNotContainType */
 			if (!isset($qb)) {
 				$qb = $this->prepareListOfIdsQuery($fdnsSlice);
 				continue;