diff --git a/app/assets/javascripts/directives/cart.coffee.erb b/app/assets/javascripts/directives/cart.coffee.erb
index 06a411c81..9afdd9e36 100644
--- a/app/assets/javascripts/directives/cart.coffee.erb
+++ b/app/assets/javascripts/directives/cart.coffee.erb
@@ -6,6 +6,11 @@ Application.Directives.directive 'cart', [ '$rootScope', '$uibModal', 'dialogs',
       slot: '='
       slotSelectionTime: '='
       events: '='
+      user: '='
+      modePlans: '='
+      plan: '='
+      planSelectionTime: '='
+      settings: '='
       onSlotAddedToCart: '='
       onSlotRemovedFromCart: '='
       onSlotStartToModify: '='
@@ -14,12 +19,9 @@ Application.Directives.directive 'cart', [ '$rootScope', '$uibModal', 'dialogs',
       onSlotModifyCancel: '='
       onSlotModifyUnselect: '='
       onSlotCancelSuccess: '='
-      user: '='
-      modePlans: '='
-      plan: '='
-      planSelectionTime: '='
       afterPayment: '='
-      settings: '='
+      reservableId: '@'
+      reservableType: '@'
     templateUrl: '<%= asset_path "shared/_cart.html" %>'
     link: ($scope, element, attributes) ->
       ## will store the user's plan if he choosed to buy one
@@ -63,11 +65,11 @@ Application.Directives.directive 'cart', [ '$rootScope', '$uibModal', 'dialogs',
       ##
       # Remove the provided slot from the shopping cart (state transition from 'about to be reserved' to free)
       # and decrement the total amount of the cart if needed.
-      # @param machineSlot {Object} fullCalendar event object
+      # @param slot {Object} fullCalendar event object
       # @param index {number} index of the slot in the reservation array
       # @param [event] {Object} see https://docs.angularjs.org/guide/expression#-event-
       ##
-      $scope.removeMachineSlot = (machineSlot, index, event)->
+      $scope.removeSlot = (slot, index, event)->
         event.preventDefault() if event
         $scope.events.reserved.splice(index, 1)
         # if is was the last slot, we remove any plan from the cart
@@ -75,7 +77,7 @@ Application.Directives.directive 'cart', [ '$rootScope', '$uibModal', 'dialogs',
           $scope.selectedPlan = null
           $scope.plan = null
           $scope.modePlans = false
-        $scope.onSlotRemovedFromCart(machineSlot) if typeof $scope.onSlotRemovedFromCart == 'function'
+        $scope.onSlotRemovedFromCart(slot) if typeof $scope.onSlotRemovedFromCart == 'function'
         updateCartPrice()
 
 
@@ -84,7 +86,7 @@ Application.Directives.directive 'cart', [ '$rootScope', '$uibModal', 'dialogs',
       # Checks that every selected slots were added to the shopping cart. Ie. will return false if
       # any checked slot was not validated by the user.
       ##
-      $scope.machineSlotsValid = ->
+      $scope.isSlotsValid = ->
         isValid = true
         angular.forEach $scope.events.reserved, (m)->
           isValid = false if !m.isValid
@@ -101,7 +103,7 @@ Application.Directives.directive 'cart', [ '$rootScope', '$uibModal', 'dialogs',
       ##
       # Validates the shopping chart and redirect the user to the payment step
       ##
-      $scope.payMachine = ->
+      $scope.payCart = ->
         # first, we check that a user was selected
         if Object.keys($scope.user).length > 0
           reservation = mkReservation($scope.user, $scope.events.reserved, $scope.selectedPlan)
@@ -121,7 +123,7 @@ Application.Directives.directive 'cart', [ '$rootScope', '$uibModal', 'dialogs',
       ##
       # When modifying an already booked reservation, confirm the modification.
       ##
-      $scope.modifyMachineSlot = ->
+      $scope.modifySlot = ->
         Slot.update {id: $scope.events.modifiable.id},
           slot:
             start_at: $scope.events.placable.start
@@ -138,7 +140,7 @@ Application.Directives.directive 'cart', [ '$rootScope', '$uibModal', 'dialogs',
       ##
       # Cancel the current booking modification, reseting the whole process
       ##
-      $scope.cancelModifyMachineSlot = ->
+      $scope.cancelModifySlot = ->
         $scope.onSlotModifyCancel() if typeof $scope.onSlotModifyCancel == 'function'
         $scope.events.placable = null
         $scope.events.modifiable = null
@@ -207,7 +209,7 @@ Application.Directives.directive 'cart', [ '$rootScope', '$uibModal', 'dialogs',
               $scope.onSlotAddedToCart() if typeof $scope.onSlotAddedToCart == 'function'
             else
               # slot is in the cart, remove it
-              $scope.removeMachineSlot($scope.slot, index)
+              $scope.removeSlot($scope.slot, index)
             # finally, we update the prices
             updateCartPrice()
           else if !$scope.slot.is_reserved && $scope.events.modifiable
@@ -222,7 +224,7 @@ Application.Directives.directive 'cart', [ '$rootScope', '$uibModal', 'dialogs',
           else if $scope.slot.is_reserved and $scope.events.modifiable and $scope.slot.is_reserved._id == $scope.events.modifiable._id
             # slot is reserved and currently modified
             # -> we cancel the modification
-            $scope.cancelModifyMachineSlot()
+            $scope.cancelModifySlot()
           else if $scope.slot.is_reserved and (slotCanBeModified($scope.slot) or slotCanBeCanceled($scope.slot)) and !$scope.events.modifiable and $scope.events.reserved.length == 0
             # slot is reserved and is ok to be modified or cancelled
             # but we are not currently running a modification or having any slots in the cart
@@ -349,8 +351,8 @@ Application.Directives.directive 'cart', [ '$rootScope', '$uibModal', 'dialogs',
       mkReservation = (member, slots, plan = null) ->
         reservation =
           user_id: member.id
-          reservable_id: (slots[0].machine.id if slots.length > 0)
-          reservable_type: 'Machine'
+          reservable_id: $scope.reservableId
+          reservable_type: $scope.reservableType
           slots_attributes: []
           plan_id: (plan.id if plan)
         angular.forEach slots, (slot, key) ->
diff --git a/app/assets/templates/machines/reserve.html.erb b/app/assets/templates/machines/reserve.html.erb
index 741c8ebf1..7c1d00ff5 100644
--- a/app/assets/templates/machines/reserve.html.erb
+++ b/app/assets/templates/machines/reserve.html.erb
@@ -55,7 +55,9 @@
           on-slot-modify-cancel="cancelModifyMachineSlot"
           on-slot-modify-unselect="changeModifyMachineSlot"
           on-slot-cancel-success="markSlotAsRemoved"
-          after-payment="afterPayment"></cart>
+          after-payment="afterPayment"
+          reservable-id="{{machine.id}}"
+          reservable-type="Machine"></cart>
 
     <uib-alert type="warning m">
       <p class="text-sm">
diff --git a/app/assets/templates/shared/_cart.html.erb b/app/assets/templates/shared/_cart.html.erb
index 0807c31a5..94f023025 100644
--- a/app/assets/templates/shared/_cart.html.erb
+++ b/app/assets/templates/shared/_cart.html.erb
@@ -33,13 +33,13 @@
         <button class="btn btn-valid btn-warning btn-block text-u-c r-b" ng-click="validateSlot(machineSlot)" ng-if="!machineSlot.isValid" translate>{{ 'confirm_this_slot' }}</button>
       </div>
 
-      <div class="clear"><a class="pull-right m-b-sm text-u-l ng-scope m-r-sm" href="#" ng-click="removeMachineSlot(machineSlot, $index, $event)" ng-if="machineSlot.isValid" translate>{{ 'remove_this_slot' }}</a></div>
+      <div class="clear"><a class="pull-right m-b-sm text-u-l ng-scope m-r-sm" href="#" ng-click="removeSlot(machineSlot, $index, $event)" ng-if="machineSlot.isValid" translate>{{ 'remove_this_slot' }}</a></div>
     </div>
 
-    <coupon show="machineSlotsValid() && (!modePlans || selectedPlan)" coupon="coupon.applied" total="totalNoCoupon" user-id="{{user.id}}"></coupon>
+    <coupon show="isSlotsValid() && (!modePlans || selectedPlan)" coupon="coupon.applied" total="totalNoCoupon" user-id="{{user.id}}"></coupon>
 
     <span ng-hide="fablabWithoutPlans">
-      <div ng-if="machineSlotsValid() && !user.subscribed_plan" ng-show="!modePlans">
+      <div ng-if="isSlotsValid() && !user.subscribed_plan" ng-show="!modePlans">
         <p class="font-sbold text-base l-h-2x" translate>{{ 'to_benefit_from_attractive_prices' }}</p>
         <div><button class="btn btn-warning-full rounded btn-block text-xs" ng-click="showPlans()" translate>{{ 'view_our_subscriptions' }}</button></div>
         <p class="font-bold text-base text-u-c text-center m-b-xs" translate>{{ 'or' }}</p>
@@ -59,7 +59,7 @@
   </div>
 
   <div class="panel-footer no-padder" ng-if="events.reserved.length > 0">
-    <button class="btn btn-valid btn-info btn-block p-l btn-lg text-u-c r-b text-base" ng-click="payMachine()" ng-if="machineSlotsValid() && (!modePlans || selectedPlan)">{{ 'confirm_and_pay' | translate }} {{amountTotal | currency}}</button>
+    <button class="btn btn-valid btn-info btn-block p-l btn-lg text-u-c r-b text-base" ng-click="payCart()" ng-if="isSlotsValid() && (!modePlans || selectedPlan)">{{ 'confirm_and_pay' | translate }} {{amountTotal | currency}}</button>
   </div>
 
   <div class="widget-content no-bg auto wrapper" ng-if="paidMachineSlots">
@@ -99,7 +99,7 @@
       <div class="panel-body">
         <div class="font-sbold text-u-c">{{ 'datetime_to_time' | translate:{START_DATETIME:(events.modifiable.start | amDateFormat:'LLLL'), END_TIME:(events.modifiable.end | amDateFormat:'LT') } }}</div>
       </div>
-      <div class="clear"><a class="pull-right m-b-sm text-u-l ng-scope m-r-sm" href="#" ng-click="cancelModifyMachineSlot($event)" translate>{{ 'cancel_my_modification' }}</a></div>
+      <div class="clear"><a class="pull-right m-b-sm text-u-l ng-scope m-r-sm" href="#" ng-click="cancelModifySlot($event)" translate>{{ 'cancel_my_modification' }}</a></div>
     </div>
 
     <div class="widget-content no-bg">
@@ -134,9 +134,9 @@
 
 
   <div class="panel-footer no-padder" ng-if="events.modifiable && events.placable">
-    <button class="btn btn-invalid btn-default btn-block p-l btn-lg text-u-c r-n text-base" ng-click="cancelModifyMachineSlot()" translate>{{ 'cancel' }}</button>
+    <button class="btn btn-invalid btn-default btn-block p-l btn-lg text-u-c r-n text-base" ng-click="cancelModifySlot()" translate>{{ 'cancel' }}</button>
     <div>
-      <button class="btn btn-valid btn-info btn-block p-l btn-lg text-u-c r-b text-base" ng-click="modifyMachineSlot()" translate>{{ 'confirm_my_modification' }}</button>
+      <button class="btn btn-valid btn-info btn-block p-l btn-lg text-u-c r-b text-base" ng-click="modifySlot()" translate>{{ 'confirm_my_modification' }}</button>
     </div>
   </div>
 
diff --git a/app/controllers/api/prices_controller.rb b/app/controllers/api/prices_controller.rb
index 19acd769e..7390af51a 100644
--- a/app/controllers/api/prices_controller.rb
+++ b/app/controllers/api/prices_controller.rb
@@ -44,7 +44,7 @@ class API::PricesController < API::ApiController
       @amount = {elements: nil, total: 0, before_coupon: 0}
     else
       _reservable = _price_params[:reservable_type].constantize.find(_price_params[:reservable_id])
-      @amount = Price.compute(current_user.is_admin?, _user, _reservable, _price_params[:slots_attributes], _price_params[:plan_id], _price_params[:nb_reserve_places], _price_params[:tickets_attributes], coupon_params[:coupon_code])
+      @amount = Price.compute(current_user.is_admin?, _user, _reservable, _price_params[:slots_attributes] || [], _price_params[:plan_id], _price_params[:nb_reserve_places], _price_params[:tickets_attributes], coupon_params[:coupon_code])
     end