diff --git a/lib/bank_audi.rb b/lib/bank_audi.rb
index 3f5ab4d..1d22f9e 100644
--- a/lib/bank_audi.rb
+++ b/lib/bank_audi.rb
@@ -96,7 +96,7 @@ def valid_vpc_secure_hash?
       end
 
       def valid_vpc_txn_response_code?
-        !(vpc_txn_response_code == '7' || vpc_txn_response_code.blank?)
+        vpc_txn_response_code == '0'
       end
 
       def sort_keys(attributes)
diff --git a/lib/bank_audi/version.rb b/lib/bank_audi/version.rb
index 8c9ab2e..9f5fdfb 100644
--- a/lib/bank_audi/version.rb
+++ b/lib/bank_audi/version.rb
@@ -1,3 +1,3 @@
 module BankAudi
-  VERSION = "0.2.3"
+  VERSION = "0.2.4"
 end
diff --git a/spec/bank_audi_spec.rb b/spec/bank_audi_spec.rb
index bdc22b3..8b5dc02 100644
--- a/spec/bank_audi_spec.rb
+++ b/spec/bank_audi_spec.rb
@@ -83,6 +83,13 @@ def valid(request)
       @response = BankAudi::Response.new
     end
 
+    def valid(response)
+      response.attributes = { :access_code => 'XXXXXX', :amount => 100, :merchant_txn_ref => 'merchant-txn-ref',
+        :merchant => 'XXXXXX', :order_info => 'order-info', :return_url => 'http://www.google.com',
+        :vpc_secure_hash => 'B2384E5659611034CFFC95842C66A4BA', :vpc_txn_response_code => '0' }
+      response
+    end
+
     it 'should initialize with default attributes' do
       [:secret_code].each do |attribute|
         @response.send(attribute).should_not be_blank
@@ -96,14 +103,19 @@ def valid(request)
     end
 
     it 'should be valid' do
-      @response.attributes = { :access_code => 'XXXXXX', :amount => 100, :merchant_txn_ref => 'merchant-txn-ref',
-        :merchant => 'XXXXXX', :order_info => 'order-info', :return_url => 'http://www.google.com',
-        :vpc_secure_hash => '82688C2F8F74B120E20C05CE7E4DC4F7', :vpc_txn_response_code => 'M' }
-      @response.should be_valid
+      valid(@response).should be_valid
     end
 
     it 'should be invalid' do
       @response.should_not be_valid
+
+      response = valid(@response)
+      response.attributes[:vpc_txn_response_code] = 'M'
+      response.should_not be_valid
+
+      response = valid(@response)
+      response.attributes[:amount] = 200
+      response.should_not be_valid
     end
   end