diff --git a/addons/mail/static/src/views/form/form_renderer.scss b/addons/mail/static/src/views/form/form_renderer.scss
index fe73755d55e..32d0d0f2f58 100644
--- a/addons/mail/static/src/views/form/form_renderer.scss
+++ b/addons/mail/static/src/views/form/form_renderer.scss
@@ -37,7 +37,7 @@
         border-top: 1px solid $border-color;
     }
 
-    &:not(.o-aside):not(.o-full-width) .o_ChatterContainer {
+    &:not(.o-aside):not(.o-full-width) .o-mail-Chatter {
         @include make-container-max-widths();
 
         margin-left: auto;
diff --git a/addons/mail/static/src/web/chatter.scss b/addons/mail/static/src/web/chatter.scss
index a03f6f9089c..894c2e1466e 100644
--- a/addons/mail/static/src/web/chatter.scss
+++ b/addons/mail/static/src/web/chatter.scss
@@ -1,10 +1,3 @@
-.o-mail-Chatter {
-    @include make-container-max-widths();
-
-    margin-left: auto;
-    margin-right: auto;
-}
-
 .o-mail-Chatter .o-mail-Message-body [summary~="o_mail_notification"] {
     display: none;
 }