diff --git a/app/models/registration.rb b/app/models/registration.rb
index 2f2d5c68..d02fa8bb 100644
--- a/app/models/registration.rb
+++ b/app/models/registration.rb
@@ -29,6 +29,7 @@ class Registration < ActiveRecord::Base
   validate :registration_limit_not_exceed, on: :create
 
   after_create :set_week, :subscribe_to_conference, :send_registration_mail
+  after_destroy :destroy_purchased_tickets
 
   def week
     created_at.strftime('%W').to_i
@@ -36,6 +37,11 @@ class Registration < ActiveRecord::Base
 
   private
 
+  def destroy_purchased_tickets
+    ticket_purchased = TicketPurchase.where(conference_id: conference_id, user_id: user.id)
+    ticket_purchased.destroy_all
+  end
+
   def subscribe_to_conference
     Subscription.create(conference_id: conference.id, user_id: user.id)
   end
diff --git a/spec/models/registration_spec.rb b/spec/models/registration_spec.rb
index 1bf9e88f..665b4e4b 100644
--- a/spec/models/registration_spec.rb
+++ b/spec/models/registration_spec.rb
@@ -3,6 +3,10 @@
 require 'spec_helper'
 
 describe 'Registration' do
+
+  let!(:user) { create(:user) }
+  let!(:conference) { create(:conference) }
+  let!(:registration1) { create(:registration, conference: conference, user: user) }
   describe 'validations' do
     it 'has a valid factory' do
       expect(build(:registration)).to be_valid
@@ -10,16 +14,28 @@ describe 'Registration' do
 
     describe 'registration_limit_not_exceed' do
       it 'is not valid when limit exceeded' do
-        conference = build(:conference)
         conference.registration_limit = 1
-        registration1 = build(:registration, conference: conference)
-        registration1.save
-        registration2 = build(:registration, conference: conference)
-        registration2.save
-        expect(conference.registrations.size).to be 1
-        expect(registration2.valid?).to be false
-        expect(registration2.errors.full_messages).to eq(['Registration limit exceeded'])
+        expect { create(:registration, conference: conference, user: user) }.to raise_error
+        expect(user.registrations.size).to be 1
       end
     end
   end
+
+  describe '#destroy_purchased_tickets' do
+    it 'destroys purchased tickets if tickets are purchased' do
+      create(:ticket_purchase, conference: conference, user: user)
+      expect(user.registrations.size).to be 1
+      expect(user.ticket_purchases.size).to be 1
+      registration1.destroy
+      expect(user.registrations.size).to be 0
+      expect(user.ticket_purchases.size).to be 0
+    end
+    it 'destroys no tickets if no tickets are purchased' do
+      expect(user.registrations.size).to be 1
+      expect(user.ticket_purchases.size).to be 0
+      registration1.destroy
+      expect(user.registrations.size).to be 0
+      expect(user.ticket_purchases.size).to be 0
+    end
+  end
 end