diff --git a/lib/aba_file_validator.ex b/lib/aba_file_validator.ex
index 4c044d8..683a9c7 100644
--- a/lib/aba_file_validator.ex
+++ b/lib/aba_file_validator.ex
@@ -4,12 +4,12 @@ defmodule AbaFileValidator do
   """
 
   @doc """
-  Hello world.
+  Get a description for a given transaction code
 
   ## Examples
 
       iex> AbaFileValidator.get_transaction_code_description("11")
-      :not_provided
+      :error
 
       iex> AbaFileValidator.get_transaction_code_description(13)
       "Externally initiated debit items"
@@ -33,5 +33,5 @@ defmodule AbaFileValidator do
   def get_transaction_code_description("56"), do: "Dividend"
   def get_transaction_code_description(57), do: "Debenture/Note Interest"
   def get_transaction_code_description("57"), do: "Debenture/Note Interest"
-  def get_transaction_code_description(_), do: :not_provided
+  def get_transaction_code_description(_), do: :error
 end
diff --git a/test/aba_file_validator_test.exs b/test/aba_file_validator_test.exs
index a58bc76..577132a 100644
--- a/test/aba_file_validator_test.exs
+++ b/test/aba_file_validator_test.exs
@@ -3,7 +3,7 @@ defmodule AbaFileValidatorTest do
   doctest AbaFileValidator
 
   test "transaction code description" do
-    assert AbaFileValidator.get_transaction_code_description(11) == :not_provided
+    assert AbaFileValidator.get_transaction_code_description(11) == :error
     assert AbaFileValidator.get_transaction_code_description(13) == "Externally initiated debit items"
     assert AbaFileValidator.get_transaction_code_description("13") == "Externally initiated debit items"
     assert AbaFileValidator.get_transaction_code_description(50) == "Externally initiated credit items with the exception of those bearing Transaction Codes"