diff --git a/app/assets/javascripts/darkswarm/controllers/checkout/billing_controller.js.coffee b/app/assets/javascripts/darkswarm/controllers/checkout/billing_controller.js.coffee
index 8464fce1f8..4e7332be27 100644
--- a/app/assets/javascripts/darkswarm/controllers/checkout/billing_controller.js.coffee
+++ b/app/assets/javascripts/darkswarm/controllers/checkout/billing_controller.js.coffee
@@ -1,5 +1,6 @@
-angular.module('Darkswarm').controller "BillingCtrl", ($scope, $timeout) ->
-  angular.extend(this, new FieldsetMixin($scope))
+angular.module('Darkswarm').controller "BillingCtrl", ($scope, $timeout, $controller) ->
+  angular.extend this, $controller('FieldsetMixin', {$scope: $scope})
+
   $scope.name = "billing"
   $scope.nextPanel = "shipping"
 
diff --git a/app/assets/javascripts/darkswarm/controllers/checkout/details_controller.js.coffee b/app/assets/javascripts/darkswarm/controllers/checkout/details_controller.js.coffee
index b39ce1dd58..a163923597 100644
--- a/app/assets/javascripts/darkswarm/controllers/checkout/details_controller.js.coffee
+++ b/app/assets/javascripts/darkswarm/controllers/checkout/details_controller.js.coffee
@@ -1,5 +1,6 @@
-angular.module('Darkswarm').controller "DetailsCtrl", ($scope, $timeout, $http, CurrentUser, AuthenticationService, SpreeUser) ->
-  angular.extend(this, new FieldsetMixin($scope))
+angular.module('Darkswarm').controller "DetailsCtrl", ($scope, $timeout, $http, CurrentUser, AuthenticationService, SpreeUser, $controller) ->
+  angular.extend this, $controller('FieldsetMixin', {$scope: $scope})
+
   $scope.name = "details"
   $scope.nextPanel = "billing"
 
diff --git a/app/assets/javascripts/darkswarm/controllers/checkout/payment_controller.js.coffee b/app/assets/javascripts/darkswarm/controllers/checkout/payment_controller.js.coffee
index 5c67975567..b95bb28338 100644
--- a/app/assets/javascripts/darkswarm/controllers/checkout/payment_controller.js.coffee
+++ b/app/assets/javascripts/darkswarm/controllers/checkout/payment_controller.js.coffee
@@ -1,5 +1,5 @@
-angular.module('Darkswarm').controller "PaymentCtrl", ($scope, $timeout, savedCreditCards, Dates) ->
-  angular.extend(this, new FieldsetMixin($scope))
+angular.module('Darkswarm').controller "PaymentCtrl", ($scope, $timeout, savedCreditCards, Dates, $controller) ->
+  angular.extend this, $controller('FieldsetMixin', {$scope: $scope})
 
   $scope.savedCreditCards = savedCreditCards
   $scope.name = "payment"
diff --git a/app/assets/javascripts/darkswarm/controllers/checkout/shipping_controller.js.coffee b/app/assets/javascripts/darkswarm/controllers/checkout/shipping_controller.js.coffee
index 6060ddff1e..58aaad5574 100644
--- a/app/assets/javascripts/darkswarm/controllers/checkout/shipping_controller.js.coffee
+++ b/app/assets/javascripts/darkswarm/controllers/checkout/shipping_controller.js.coffee
@@ -1,5 +1,6 @@
-angular.module('Darkswarm').controller "ShippingCtrl", ($scope, $timeout, ShippingMethods) ->
-  angular.extend(this, new FieldsetMixin($scope))
+angular.module('Darkswarm').controller "ShippingCtrl", ($scope, $timeout, ShippingMethods, $controller) ->
+  angular.extend this, $controller('FieldsetMixin', {$scope: $scope})
+
   $scope.ShippingMethods = ShippingMethods
   $scope.name = "shipping"
   $scope.nextPanel = "payment"
diff --git a/app/assets/javascripts/darkswarm/controllers/credit_cards_controller.js.coffee b/app/assets/javascripts/darkswarm/controllers/credit_cards_controller.js.coffee
index a5ae0ada94..72e63f4694 100644
--- a/app/assets/javascripts/darkswarm/controllers/credit_cards_controller.js.coffee
+++ b/app/assets/javascripts/darkswarm/controllers/credit_cards_controller.js.coffee
@@ -1,5 +1,6 @@
-angular.module('Darkswarm').controller "CreditCardsCtrl", ($scope, CreditCard, CreditCards) ->
-  angular.extend(this, new FieldsetMixin($scope))
+angular.module('Darkswarm').controller "CreditCardsCtrl", ($scope, CreditCard, CreditCards, $controller) ->
+  angular.extend this, $controller('FieldsetMixin', {$scope: $scope})
+
   $scope.savedCreditCards = CreditCards.saved
   $scope.confirmSetDefault = CreditCards.confirmSetDefault
   $scope.CreditCard = CreditCard
diff --git a/app/assets/javascripts/darkswarm/mixins/fieldset_mixin.js.coffee b/app/assets/javascripts/darkswarm/mixins/fieldset_mixin.js.coffee
index d8bb1b262e..adf7081e00 100644
--- a/app/assets/javascripts/darkswarm/mixins/fieldset_mixin.js.coffee
+++ b/app/assets/javascripts/darkswarm/mixins/fieldset_mixin.js.coffee
@@ -1,4 +1,4 @@
-window.FieldsetMixin = ($scope)->
+angular.module('Darkswarm').controller "FieldsetMixin", ($scope, $timeout) ->
   $scope.next = (event = false)->
     event.preventDefault() if event
     return unless $scope.nextPanel