diff --git a/lib/private/Setup/PostgreSQL.php b/lib/private/Setup/PostgreSQL.php
index 9d0e1dc412fd9..af816c7ad0432 100644
--- a/lib/private/Setup/PostgreSQL.php
+++ b/lib/private/Setup/PostgreSQL.php
@@ -79,7 +79,7 @@ public function setupDatabase($username) {
 				// Therefore we assume that the database is only used by one user/service which is Nextcloud
 				// Additional services should get installed in a separate database in order to stay secure
 				// Also see https://www.postgresql.org/docs/15/ddl-schemas.html#DDL-SCHEMAS-PATTERNS
-				$connectionMainDatabase->executeQuery('GRANT CREATE ON SCHEMA public TO ' . $this->dbUser);
+				$connectionMainDatabase->executeQuery('GRANT CREATE ON SCHEMA public TO ' . addslashes($this->dbUser));
 				$connectionMainDatabase->close();
 			}