lib/recurly/subscription/add_ons.rb in recurly-2.7.3 vs lib/recurly/subscription/add_ons.rb in recurly-2.7.4

@@ -25,10 +25,11 @@
       def << add_on
         add_on = SubscriptionAddOn.new(add_on, @subscription)
 
         exist = @add_ons.find { |a| a.add_on_code == add_on.add_on_code }
         if exist
-          exist.quantity ||= 1 and exist.quantity += 1
+          exist.quantity ||= 1
+          exist.quantity += add_on.quantity || 1
 
           if add_on.unit_amount_in_cents
             exist.unit_amount_in_cents = add_on.unit_amount_in_cents
           end
         else