diff --git a/addons/mail/static/src/models/rtc_session.js b/addons/mail/static/src/models/rtc_session.js
index ec2e64c8904..bffe383ae5b 100644
--- a/addons/mail/static/src/models/rtc_session.js
+++ b/addons/mail/static/src/models/rtc_session.js
@@ -340,7 +340,6 @@ registerModel({
          */
         callParticipantCards: many('CallParticipantCard', {
             inverse: 'rtcSession',
-            isCausal: true,
         }),
         /**
          * States whether there is currently an error with the audio element.