diff --git a/addons/mail/static/src/views/web/form/form_renderer.scss b/addons/mail/static/src/views/web/form/form_renderer.scss
index c26f76e736f..c2892b37263 100644
--- a/addons/mail/static/src/views/web/form/form_renderer.scss
+++ b/addons/mail/static/src/views/web/form/form_renderer.scss
@@ -8,12 +8,9 @@
     --ChatterTopbar-padding-right: #{$o-horizontal-padding};
 
     &.o-aside {
-        --Chatter-max-width: #{$o-form-view-sheet-max-width};
-
         flex-shrink: 0;
         flex-grow: 1;
         padding: map-get($spacers, 0);
-        max-width: var(--Chatter-max-width);
         width: $o-mail-Chatter-minWidth;
 
         .o-mail-Message.o-not-discussion {
diff --git a/addons/web/static/src/views/form/form.variables.scss b/addons/web/static/src/views/form/form.variables.scss
index eb33a399578..55ad8093c80 100644
--- a/addons/web/static/src/views/form/form.variables.scss
+++ b/addons/web/static/src/views/form/form.variables.scss
@@ -1,4 +1,5 @@
 $o-sheet-vpadding: $o-spacer * 1.5 !default;
 
+$o-form-renderer-max-width: 2600px !default;
 $o-form-view-sheet-max-width: 1534px !default;
 $o-form-picture-size: 90px !default;
diff --git a/addons/web/static/src/views/form/form_controller.scss b/addons/web/static/src/views/form/form_controller.scss
index 968b6dcbf55..5965afe29d4 100644
--- a/addons/web/static/src/views/form/form_controller.scss
+++ b/addons/web/static/src/views/form/form_controller.scss
@@ -212,6 +212,10 @@
         }
     }
 
+    .o_form_renderer {
+        max-width: $o-form-renderer-max-width;
+    }
+
     // No sheet
     &.o_form_nosheet, .o_form_nosheet {
         // Since 16.3 the `o_form_nosheet` element acts as a sheet filling the