       end
 
       def validate_claim(:iat, payload) do
-        Joken.Config.validate_time_claim(payload, :iat, "Token not valid yet", fn(not_before, now) -> not_before < now end) 
+        Joken.Config.validate_time_claim(payload, "iat", "Token not valid yet", fn(not_before, now) -> not_before < now end) 
       end
 
       def validate_claim(_, _) do

      end

      def decode(binary) do
        Poison.decode!(binary, keys: :atoms!)
      end

      def claim(:iat, _payload) do

      end
    end 

    {:ok, token} = Joken.Token.encode(IatSuccessTest,  %{ "name" => "John Doe" })
    assert {:ok, _} = Joken.Token.decode(IatSuccessTest, token)

    {:ok, token} = Joken.Token.encode(IatFailureTest,  %{ "name" => "John Doe" })
    assert {:error, "Token not valid yet"} == Joken.Token.decode(IatFailureTest, token)
  end
end
