diff --git a/app/assets/stylesheets/desktop/compose.scss b/app/assets/stylesheets/desktop/compose.scss
index 337726fa881..c548e5f210c 100644
--- a/app/assets/stylesheets/desktop/compose.scss
+++ b/app/assets/stylesheets/desktop/compose.scss
@@ -397,7 +397,9 @@
       position: absolute;
       left: 0;
       top: 0;
+      border: 0px;
       border-top: 30px solid transparent;
+      @include border-radius-all(0);
     }
     #wmd-preview-scroller {
       font-size: 13px;