diff --git a/addons/web/static/src/legacy/scss/form_view.scss b/addons/web/static/src/legacy/scss/form_view.scss
index 67ed05c4bbf..8a27feb964a 100644
--- a/addons/web/static/src/legacy/scss/form_view.scss
+++ b/addons/web/static/src/legacy/scss/form_view.scss
@@ -167,10 +167,9 @@ $o-form-label-margin-right: 0px;
                     width: auto!important;
                 }
             }
-        }
-
-        .o_field_many2one .o_field_many2one_selection {
-            width: 100% !important;
+            &.o_field_many2one_selection {
+                width: 100% !important;
+            }
         }
     }