diff --git a/app/assets/javascripts/discourse/controllers/application.js.es6 b/app/assets/javascripts/discourse/controllers/application.js.es6
index 29d200ca082..115654b621b 100644
--- a/app/assets/javascripts/discourse/controllers/application.js.es6
+++ b/app/assets/javascripts/discourse/controllers/application.js.es6
@@ -1,3 +1,9 @@
 export default Ember.Controller.extend({
   styleCategory: null,
+
+  canSignUp: function() {
+    return !Discourse.SiteSettings.invite_only &&
+           Discourse.SiteSettings.allow_new_registrations &&
+           !Discourse.SiteSettings.enable_sso;
+  }.property(),
 });
diff --git a/app/assets/javascripts/discourse/controllers/header.js.es6 b/app/assets/javascripts/discourse/controllers/header.js.es6
index 90798d38f6b..47ff0ff9eaf 100644
--- a/app/assets/javascripts/discourse/controllers/header.js.es6
+++ b/app/assets/javascripts/discourse/controllers/header.js.es6
@@ -11,6 +11,9 @@ export default Discourse.Controller.extend({
   showExtraInfo: null,
   notifications: null,
   loadingNotifications: false,
+  needs: ['application'],
+
+  showSignUpButton: Em.computed.alias('controllers.application.canSignUp'),
 
   showStarButton: function() {
     return Discourse.User.current() && !this.get('topic.isPrivateMessage');
diff --git a/app/assets/javascripts/discourse/controllers/login.js.es6 b/app/assets/javascripts/discourse/controllers/login.js.es6
index 2fbf865c5e2..2515a7da632 100644
--- a/app/assets/javascripts/discourse/controllers/login.js.es6
+++ b/app/assets/javascripts/discourse/controllers/login.js.es6
@@ -8,7 +8,7 @@
   @module Discourse
 **/
 export default Discourse.Controller.extend(Discourse.ModalFunctionality, {
-  needs: ['modal', 'createAccount'],
+  needs: ['modal', 'createAccount', 'application'],
   authenticate: null,
   loggingIn: false,
   loggedIn: false,
@@ -37,8 +37,7 @@ export default Discourse.Controller.extend(Discourse.ModalFunctionality, {
   loginDisabled: Em.computed.or('loggingIn', 'loggedIn'),
 
   showSignupLink: function() {
-    return !Discourse.SiteSettings.invite_only &&
-           Discourse.SiteSettings.allow_new_registrations &&
+    return this.get('controllers.application.canSignUp') &&
            !this.get('loggingIn') &&
            this.blank('authenticate');
   }.property('loggingIn', 'authenticate'),
@@ -77,7 +76,7 @@ export default Discourse.Controller.extend(Discourse.ModalFunctionality, {
           $hidden_login_form.submit();
         }
 
-      }, function(e) {
+      }, function() {
         // Failed to login
         if (self.blank('loginName') || self.blank('loginPassword')) {
           self.flash(I18n.t('login.blank_username_or_password'), 'error');
diff --git a/app/assets/javascripts/discourse/templates/header.js.handlebars b/app/assets/javascripts/discourse/templates/header.js.handlebars
index 89e24ba4bb1..4c4d7ba97fe 100644
--- a/app/assets/javascripts/discourse/templates/header.js.handlebars
+++ b/app/assets/javascripts/discourse/templates/header.js.handlebars
@@ -41,9 +41,11 @@
         </div>
       {{/unless}}
       {{#unless currentUser}}
+        {{#if showSignUpButton}}
         <button {{action showCreateAccount}} class='btn btn-primary btn-small sign-up-button'>
           {{i18n sign_up}}
         </button>
+        {{/if}}
         <button {{action showLogin}} class='btn btn-primary btn-small login-button'>
           {{icon user}} {{i18n log_in}}
         </button>
diff --git a/test/javascripts/controllers/header-test.js.es6 b/test/javascripts/controllers/header-test.js.es6
index ead441172d6..aabbd9ad5ed 100644
--- a/test/javascripts/controllers/header-test.js.es6
+++ b/test/javascripts/controllers/header-test.js.es6
@@ -1,4 +1,6 @@
-moduleFor("controller:header", "controller:header");
+moduleFor("controller:header", "controller:header", {
+  needs: ['controller:application']
+});
 
 test("showNotifications action", function() {
   var resolveRequestWith;
diff --git a/test/javascripts/controllers/topic-test.js.es6 b/test/javascripts/controllers/topic-test.js.es6
index 6cae2006a84..cf853c0d3a1 100644
--- a/test/javascripts/controllers/topic-test.js.es6
+++ b/test/javascripts/controllers/topic-test.js.es6
@@ -1,6 +1,6 @@
 moduleFor('controller:topic', 'controller:topic', {
   needs: ['controller:header', 'controller:modal', 'controller:composer', 'controller:quote-button',
-          'controller:search', 'controller:topic-progress']
+          'controller:search', 'controller:topic-progress', 'controller:application']
 });
 
 var buildTopic = function() {