diff --git a/addons/mail/static/src/components/discuss/discuss.scss b/addons/mail/static/src/components/discuss/discuss.scss
index d57bf71ecda..ba4286c3a6d 100644
--- a/addons/mail/static/src/components/discuss/discuss.scss
+++ b/addons/mail/static/src/components/discuss/discuss.scss
@@ -2,11 +2,6 @@
 // Layout
 // ------------------------------------------------------------------
 
-.o_action_manager {
-    // bug with scrollable inside discuss mobile without this...
-    min-height: 0;
-}
-
 .o-autogrow {
     flex: 1 1 auto;
 }
@@ -87,7 +82,7 @@
 }
 
 .o_Discuss_thread {
-    flex: 1 1 auto;
+    flex: 1 1 0;
     min-width: 0;
 
     &.o-mobile {
@@ -97,7 +92,7 @@
 
 .o_Discuss_notificationList {
     width: map-get($sizes, 100);
-    flex: 1 1 auto;
+    flex: 1 1 0;
 }
 
 // ------------------------------------------------------------------