diff --git a/models/chunter/src/index.ts b/models/chunter/src/index.ts
index 577b5544a1..4d8e84ac50 100644
--- a/models/chunter/src/index.ts
+++ b/models/chunter/src/index.ts
@@ -474,6 +474,7 @@ export function createModel (builder: Builder): void {
       hidden: false,
       txClasses: [core.class.TxCreateDoc],
       objectClass: chunter.class.ChatMessage,
+      attachedToClass: chunter.class.DirectMessage,
       providers: {
         [notification.providers.EmailNotification]: false,
         [notification.providers.BrowserNotification]: true,