diff --git a/app/assets/javascripts/discourse/app/controllers/composer.js b/app/assets/javascripts/discourse/app/controllers/composer.js
index 6f8d6e245ed..cd260683d62 100644
--- a/app/assets/javascripts/discourse/app/controllers/composer.js
+++ b/app/assets/javascripts/discourse/app/controllers/composer.js
@@ -689,7 +689,8 @@ export default Controller.extend({
       }
 
       if (currentTopic.id !== composer.get("topic.id")) {
-        const message = I18n.t("composer.posting_not_on_topic");
+        const message =
+          "<h1>" + I18n.t("composer.posting_not_on_topic") + "</h1>";
 
         let buttons = [
           {
diff --git a/app/assets/stylesheets/common/base/modal.scss b/app/assets/stylesheets/common/base/modal.scss
index 34b2aef3f53..066f7ae38f7 100644
--- a/app/assets/stylesheets/common/base/modal.scss
+++ b/app/assets/stylesheets/common/base/modal.scss
@@ -294,22 +294,32 @@
 }
 
 .reply-where-modal {
-  .modal-footer {
-    a {
-      display: block;
+  max-width: 400px;
+
+  h1 {
+    margin: 0;
+    font-size: $font-up-2;
+  }
+
+  .d-modal-cancel {
+    width: 100%;
+    margin: 0.5em 0;
+  }
+
+  .btn {
+    display: block;
+    text-align: left;
+    font-size: $font-up-1;
+    line-height: $line-height-medium;
+    margin-bottom: 0.75em;
+    font-weight: bold;
+    overflow: hidden;
+    width: 100%;
+    &:first-of-type {
+      margin-top: 0.25em;
     }
-    .d-modal-cancel {
-      margin: 1em 0 0.5em;
-    }
-    .btn {
-      text-align: left;
-      font-size: $font-up-2;
-      line-height: $line-height-medium;
-      margin-bottom: 10px;
-      font-weight: bold;
-      .topic-title {
-        font-weight: normal;
-      }
+    .topic-title {
+      font-weight: normal;
     }
   }
 }