diff --git a/addons/mail/static/src/less/composer.less b/addons/mail/static/src/less/composer.less
index a7ca9fb9787..71af37fc054 100644
--- a/addons/mail/static/src/less/composer.less
+++ b/addons/mail/static/src/less/composer.less
@@ -51,7 +51,7 @@
             border: none;
         }
         .o_composer_button_full_composer {
-            .o-position-absolute(0, 0);
+            .o-position-absolute(auto, 0);
         }
         @media (max-width: @screen-xs-max) {
             .o_composer_button_send {