diff --git a/src/components/post_status_form/post_status_form.vue b/src/components/post_status_form/post_status_form.vue
index bd39759e..79049f05 100644
--- a/src/components/post_status_form/post_status_form.vue
+++ b/src/components/post_status_form/post_status_form.vue
@@ -170,7 +170,7 @@
             cols="1"
             :disabled="posting && !optimisticPosting"
             class="form-post-body"
-            :class="{ 'scrollable-form': !!maxHeight }"
+            :class="{ 'scrollable-form': !!maxHeight, '-has-subject': subjectVisible }"
             @keydown.exact.enter="submitOnEnter && postStatus($event, newStatus)"
             @keydown.meta.enter="postStatus($event, newStatus)"
             @keydown.ctrl.enter="!submitOnEnter && postStatus($event, newStatus)"
@@ -584,6 +584,11 @@
     line-height: 1.85;
   }
 
+  .form-post-subject {
+    border-bottom-left-radius: 0;
+    border-bottom-right-radius: 0;
+  }
+
   .form-post-body {
     // TODO: make a resizable textarea component?
     box-sizing: content-box; // needed for easier computation of dynamic size
@@ -596,6 +601,11 @@
     min-height: calc(var(--post-line-height) * 1em);
     resize: none;
 
+    &.-has-subject {
+      border-top-left-radius: 0;
+      border-top-right-radius: 0;
+    }
+
     &.scrollable-form {
       overflow-y: auto;
     }