diff --git a/lib/Db/CredentialMapper.php b/lib/Db/CredentialMapper.php
index 27646cbc..4b3dd24c 100644
--- a/lib/Db/CredentialMapper.php
+++ b/lib/Db/CredentialMapper.php
@@ -39,7 +39,7 @@ class CredentialMapper extends Mapper {
 	 */
 	public function getRandomCredentialByVaultId($vault_id, $user_id) {
 		$sql = 'SELECT * FROM `*PREFIX*passman_credentials` ' .
-			'WHERE `user_id` = ? and vault_id = ? AND shared_key is NULL';
+			'WHERE `user_id` = ? and vault_id = ? AND shared_key is NULL LIMIT 20';
 		$entities = $this->findEntities($sql, [$user_id, $vault_id]);
 		$count = count($entities);
 		$entities = array_splice($entities, rand(0, $count), 1);