diff --git a/src/components/post_status_form/post_status_form.vue b/src/components/post_status_form/post_status_form.vue
index 82170835..077757ec 100644
--- a/src/components/post_status_form/post_status_form.vue
+++ b/src/components/post_status_form/post_status_form.vue
@@ -600,6 +600,8 @@
     height: calc(var(--post-line-height) * 1em);
     min-height: calc(var(--post-line-height) * 1em);
     resize: none;
+    border-top-left-radius: 0;
+    border-top-right-radius: 0;
 
     &.-has-subject {
       border-top-left-radius: 0;