diff --git a/opentech/apply/activity/templates/activity/include/comment_form.html b/opentech/apply/activity/templates/activity/include/comment_form.html
index 2dc4ff215d33c95824c89a3766ba6bf95d3f8abc..2db10184cc3551622e160301d2301ec269d119ae 100644
--- a/opentech/apply/activity/templates/activity/include/comment_form.html
+++ b/opentech/apply/activity/templates/activity/include/comment_form.html
@@ -1,5 +1,5 @@
 <form class="form form--comments" method="post" id="comment-form">
     {% csrf_token %}
     {{ comment_form }}
-    <input id="comment-form-submit" name="form-submitted" type="submit" form="comment-form" value="Comment">
+    <input id="comment-form-submit" name="form-submitted" form="comment-form" class="button button--primary" type="submit" value="Comment">
 </form>