diff --git a/r2/r2/public/static/css/reddit.css b/r2/r2/public/static/css/reddit.css
index 4c22e12a1..dd1a5308b 100755
--- a/r2/r2/public/static/css/reddit.css
+++ b/r2/r2/public/static/css/reddit.css
@@ -2684,6 +2684,10 @@ body.rulespage-body {
     color: #369;
 }
 
+button.button[disabled] {
+    color: gray;
+}
+
 .button #cover {
     position: relative; 
  }
diff --git a/r2/r2/public/static/js/login.js b/r2/r2/public/static/js/login.js
index f25886808..639c4b525 100644
--- a/r2/r2/public/static/js/login.js
+++ b/r2/r2/public/static/js/login.js
@@ -210,6 +210,8 @@ r.ui.RegisterForm = function() {
     this.checkUsernameDebounced = _.debounce($.proxy(this, 'checkUsername'), 500)
     this.$user = this.$el.find('[name="user"]')
     this.$user.on('keyup', $.proxy(this, 'usernameChanged'))
+    this.$submit = this.$el.find('.submit button')
+
 }
 r.ui.RegisterForm.prototype = $.extend(new r.ui.Form(), {
     usernameChanged: function() {
@@ -221,6 +223,7 @@ r.ui.RegisterForm.prototype = $.extend(new r.ui.Form(), {
         }
 
         this.$el.find('.error.field-user').hide()
+        this.$submit.attr('disabled', false)
         this.$el.removeClass('name-available name-taken')
         this.checkUsernameDebounced(name)
         this.$el.toggleClass('name-checking', !!name)
@@ -240,8 +243,10 @@ r.ui.RegisterForm.prototype = $.extend(new r.ui.Form(), {
     displayUsernameStatus: function(result) {
         if (result.json && result.json.errors) {
             this.showErrors(result.json.errors)
+            this.$submit.attr('disabled', true)
         } else {
             this.$el.addClass(result ? 'name-available' : 'name-taken')
+            this.$submit.attr('disabled', result == false)
         }
     },