diff --git a/plugins/poll/assets/javascripts/controllers/poll.js.es6 b/plugins/poll/assets/javascripts/controllers/poll.js.es6
index fe820beaa61..c015c393f66 100644
--- a/plugins/poll/assets/javascripts/controllers/poll.js.es6
+++ b/plugins/poll/assets/javascripts/controllers/poll.js.es6
@@ -107,6 +107,11 @@ export default Ember.Controller.extend({
 
   castVotesDisabled: Em.computed.not("canCastVotes"),
 
+  @computed("castVotesDisabled")
+  castVotesButtonClass(castVotesDisabled) {
+    return `cast-votes ${castVotesDisabled ? '' : 'btn-primary'}`;
+  },
+
   @computed("loading", "post.user_id", "post.topic.archived")
   canToggleStatus(loading, userId, topicArchived) {
     return this.currentUser &&
diff --git a/plugins/poll/assets/javascripts/discourse/templates/poll.hbs b/plugins/poll/assets/javascripts/discourse/templates/poll.hbs
index dc8c4159138..68603747587 100644
--- a/plugins/poll/assets/javascripts/discourse/templates/poll.hbs
+++ b/plugins/poll/assets/javascripts/discourse/templates/poll.hbs
@@ -41,7 +41,7 @@
 <div class="poll-buttons">
   {{#if isMultiple}}
     {{#unless hideResultsDisabled}}
-      {{d-button class="cast-votes" title="poll.cast-votes.title" label="poll.cast-votes.label" disabled=castVotesDisabled action="castVotes"}}
+      {{d-button class=castVotesButtonClass title="poll.cast-votes.title" label="poll.cast-votes.label" disabled=castVotesDisabled action="castVotes"}}
     {{/unless}}
   {{/if}}