diff --git a/sib-chat.js b/sib-chat.js
index 036e9f2426c6624f0b9ff98c9c8c03c1eb9391fc..fd97af75f2f39da11ddf1f712e4e635423668b22 100644
--- a/sib-chat.js
+++ b/sib-chat.js
@@ -195,6 +195,7 @@ export const SibChat = {
       'authentication': this.element.dataset.authentication,
       'password': idToken,
       'allow_chat_pending_contacts': true,
+      'allow_non_roster_messaging': true,
       'allow_dragresize': false,
       'allow_logout': false,
       'archived_messages_page_size': 30,