diff --git a/lib/fake_braintree/customer.rb b/lib/fake_braintree/customer.rb
index 289a207..2ced325 100644
--- a/lib/fake_braintree/customer.rb
+++ b/lib/fake_braintree/customer.rb
@@ -81,7 +81,14 @@ def verify_credit_card?(customer_hash)
     end
 
     def has_invalid_credit_card?(customer_hash)
-      ! FakeBraintree::VALID_CREDIT_CARDS.include?(@customer_hash["credit_card"]["number"])
+      has_credit_card_number? &&
+        ! FakeBraintree::VALID_CREDIT_CARDS.include?(@customer_hash["credit_card"]["number"])
+    end
+
+    def has_credit_card_number?
+      @customer_hash.key?("credit_card") &&
+        @customer_hash["credit_card"].is_a?(Hash) &&
+        @customer_hash["credit_card"].key?("number")
     end
   end
 end
diff --git a/spec/fake_braintree/customer_spec.rb b/spec/fake_braintree/customer_spec.rb
index 795f433..e2225d5 100644
--- a/spec/fake_braintree/customer_spec.rb
+++ b/spec/fake_braintree/customer_spec.rb
@@ -5,7 +5,7 @@
 
   it "successfully creates a customer" do
     result = Braintree::Customer.create(:credit_card => { :number => TEST_CC_NUMBER,
-                                                          :expiration_date => expiration_date })
+                                                          :expiration_date => '04/2016'})
     result.should be_success
   end
 
@@ -16,8 +16,8 @@
 
   it "creates a customer using an expiration month and year" do
     result = Braintree::Customer.create(:credit_card => { :number => TEST_CC_NUMBER,
-                                                          :expiration_month => expiration_month,
-                                                          :expiration_year => expiration_year })
+                                                          :expiration_month => '04',
+                                                          :expiration_year => '2016'})
     result.should be_success
   end
 
@@ -38,55 +38,34 @@
     billing_address.street_address.should == "1 E Main St"
     billing_address.postal_code.should == "60622"
   end
+end
 
-  context "when passed :verify_card => true" do
-    it "accepts valid cards" do
-      create_customer(:options => { :verify_card => true }).should be_success
-    end
-
-    it "rejects invalid cards" do
-      create_customer_with_invalid_card(:options => { :verify_card => true }).should_not be_success
-    end
+describe "Braintree::Customer.create", "when passed :verify_card => true" do
+  it "accepts valid cards" do
+    create_customer(:options => { :verify_card => true }).should be_success
   end
 
-  context "when FakeBraintree.verify_all_cards == true" do
-    before { FakeBraintree.verify_all_cards! }
-
-    it "accepts valid cards" do
-      create_customer.should be_success
-    end
-
-    it "rejects invalid cards" do
-      create_customer_with_invalid_card.should_not be_success
-    end
+  it "rejects invalid cards" do
+    create_customer_with_invalid_card(:options => { :verify_card => true }).should_not be_success
   end
+end
 
-  def create_customer(options = {})
-    options[:number] ||= TEST_CC_NUMBER
-    options[:expiration_date] ||= expiration_date
-    Braintree::Customer.create(:credit_card => options)
-  end
+describe "Braintree::Customer.create", "when FakeBraintree.verify_all_cards == true" do
+  before { FakeBraintree.verify_all_cards! }
 
-  def create_customer_with_invalid_card(options = {})
-    options[:number] = '123456'
-    options[:expiration_date] ||= expiration_date
-    create_customer(options)
+  it "accepts valid cards" do
+    create_customer.should be_success
   end
 
-  let(:expiration_month) { "04" }
-  let(:expiration_year)  { "2016" }
-  let(:expiration_date)  { [expiration_month, expiration_year].join("/") }
+  it "rejects invalid cards" do
+    create_customer_with_invalid_card.should_not be_success
+  end
 end
 
 describe "Braintree::Customer.find" do
-  let(:expiration_date) { "04/2016" }
-
-  def create_customer(options)
-    Braintree::Customer.create(:credit_card => options)
-  end
-
   it "successfully finds a customer" do
-    result = Braintree::Customer.create(:first_name => "Bob", :last_name => "Smith")
+    result = Braintree::Customer.create(:first_name => "Bob",
+                                        :last_name => "Smith")
 
     Braintree::Customer.find(result.customer.id).first_name.should == "Bob"
   end
diff --git a/spec/fake_braintree/subscription_spec.rb b/spec/fake_braintree/subscription_spec.rb
index 4b217ec..199c6aa 100644
--- a/spec/fake_braintree/subscription_spec.rb
+++ b/spec/fake_braintree/subscription_spec.rb
@@ -1,62 +1,58 @@
 require 'spec_helper'
 
-describe FakeBraintree::SinatraApp do
-  context "Braintree::Subscription.create" do
-    let(:plan_id)                { 'plan-id-from-braintree-control-panel' }
-    let(:cc_number)              { %w(4111 1111 1111 9876).join }
-    let(:expiration_date)        { "04/2016" }
-    let(:payment_method_token)   { braintree_credit_card_token(cc_number, expiration_date) }
-    let(:payment_method_token_2) { braintree_credit_card_token(cc_number.sub('1', '5'), expiration_date) }
-
-    it "successfully creates a subscription" do
-      result = Braintree::Subscription.create(:payment_method_token => payment_method_token,
-                                              :plan_id => plan_id)
-      result.should be_success
-    end
+describe "Braintree::Subscription.create" do
+  let(:plan_id)                { 'plan-id-from-braintree-control-panel' }
+  let(:expiration_date)        { "04/2016" }
+
+  it "successfully creates a subscription" do
+    result = Braintree::Subscription.create(:payment_method_token => cc_token,
+                                            :plan_id => plan_id)
+    result.should be_success
+  end
 
-    it "assigns a Braintree-esque ID to the subscription" do
-      result = Braintree::Subscription.create(:payment_method_token => payment_method_token,
-                                              :plan_id => plan_id)
+  it "assigns a Braintree-esque ID to the subscription" do
+    result = Braintree::Subscription.create(:payment_method_token => cc_token,
+                                            :plan_id => plan_id)
 
-      result.subscription.id.should =~ /^[a-z0-9]{6}$/
-    end
+    result.subscription.id.should =~ /^[a-z0-9]{6}$/
+  end
 
-    it "assigns unique IDs to each subscription" do
-      first_result = Braintree::Subscription.create(:payment_method_token => payment_method_token,
-                                                    :plan_id => plan_id)
-      second_result = Braintree::Subscription.create(:payment_method_token => payment_method_token_2,
-                                                     :plan_id => plan_id)
+  it "assigns unique IDs to each subscription" do
+    cc_token_1 = cc_token
+    cc_token_2 = braintree_credit_card_token(TEST_CC_NUMBER.sub('1', '5'), expiration_date)
+    first_result = Braintree::Subscription.create(:payment_method_token => cc_token_1,
+                                                  :plan_id => plan_id)
+    second_result = Braintree::Subscription.create(:payment_method_token => cc_token_2,
+                                                   :plan_id => plan_id)
 
-      first_result.subscription.id.should_not == second_result.subscription.id
-    end
+    first_result.subscription.id.should_not == second_result.subscription.id
+  end
 
-    it "sets the next billing date to 1 month from now in UTC" do
-      Timecop.freeze do
-        result = Braintree::Subscription.create(:payment_method_token => payment_method_token,
-                                                :plan_id => plan_id)
+  it "sets the next billing date to 1 month from now in UTC" do
+    Timecop.freeze do
+      result = Braintree::Subscription.create(:payment_method_token => cc_token,
+                                              :plan_id => plan_id)
 
-        result.subscription.next_billing_date.to_i.should == 1.month.from_now.utc.to_i
-      end
+      result.subscription.next_billing_date.to_i.should == 1.month.from_now.utc.to_i
     end
   end
+end
 
-  context "Braintree::Subscription.find" do
-    let(:cc_number)            { %w(4111 1111 1111 9876).join }
-    let(:expiration_date)      { "04/2016" }
-    let(:payment_method_token) { braintree_credit_card_token(cc_number, expiration_date) }
-    let(:plan_id)              { 'my-plan-id' }
-    let(:subscription_result)  { Braintree::Subscription.create(:payment_method_token => payment_method_token,
-                                                                :plan_id => plan_id) }
-
-    it "can find a created subscription" do
-      subscription = Braintree::Subscription.find(subscription_result.subscription.id)
-      subscription.should_not be_nil
-      subscription.payment_method_token.should == payment_method_token
-      subscription.plan_id.should == plan_id
-    end
+describe "Braintree::Subscription.find" do
 
-    it "raises a Braintree:NotFoundError when it cannot find a subscription" do
-      expect { Braintree::Subscription.find('abc123') }.to raise_error(Braintree::NotFoundError, /abc123/)
-    end
+  it "can find a created subscription" do
+    subscription = Braintree::Subscription.find(subscription_id)
+    subscription.should_not be_nil
+    subscription.payment_method_token.should == payment_method_token
+    subscription.plan_id.should == plan_id
   end
+
+  it "raises a Braintree:NotFoundError when it cannot find a subscription" do
+    expect { Braintree::Subscription.find('abc123') }.to raise_error(Braintree::NotFoundError, /abc123/)
+  end
+
+  let(:payment_method_token) { cc_token }
+  let(:plan_id)              { 'my-plan-id' }
+  let(:subscription_id)  { Braintree::Subscription.create(:payment_method_token => payment_method_token,
+                                                          :plan_id => plan_id).subscription.id }
 end
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index d278633..e475821 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -17,6 +17,7 @@
     config.mock_with :mocha
 
     config.include BraintreeHelpers
+    config.include CustomerHelpers
 
     config.before { FakeBraintree.clear! }
   end
diff --git a/spec/support/customer_helpers.rb b/spec/support/customer_helpers.rb
new file mode 100644
index 0000000..b91a0d5
--- /dev/null
+++ b/spec/support/customer_helpers.rb
@@ -0,0 +1,12 @@
+module CustomerHelpers
+  def create_customer(credit_card_options = {})
+    credit_card_options[:number] ||= TEST_CC_NUMBER
+    credit_card_options[:expiration_date] ||= '04/2016'
+    Braintree::Customer.create(:credit_card => credit_card_options)
+  end
+
+  def create_customer_with_invalid_card(credit_card_options = {})
+    credit_card_options[:number] = '123456'
+    create_customer(credit_card_options)
+  end
+end