diff --git a/apps/files_external/lib/Service/DBConfigService.php b/apps/files_external/lib/Service/DBConfigService.php
index 3e38f4aed94d..ce975cb3fac0 100644
--- a/apps/files_external/lib/Service/DBConfigService.php
+++ b/apps/files_external/lib/Service/DBConfigService.php
@@ -207,7 +207,7 @@ public function addMount($mountPoint, $storageBackend, $authBackend, $priority,
 				'type' => $builder->createNamedParameter($type, IQueryBuilder::PARAM_INT)
 			]);
 		$query->execute();
-		return (int)$this->connection->lastInsertId('external_mounts');
+		return (int)$this->connection->lastInsertId('*PREFIX*external_mounts');
 	}
 
 	/**