diff --git a/src/lp/packet.cpp b/src/lp/packet.cpp
index 7b71c72..c17f1bd 100644
--- a/src/lp/packet.cpp
+++ b/src/lp/packet.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /**
- * Copyright (c) 2013-2016 Regents of the University of California.
+ * Copyright (c) 2013-2017 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -130,10 +130,10 @@
 }
 
 bool
-Packet::comparePos(const Block& first, const uint64_t second)
+Packet::comparePos(uint64_t first, const Block& second)
 {
-  detail::FieldInfo firstInfo(first.type());
-  detail::FieldInfo secondInfo(second);
+  detail::FieldInfo firstInfo(first);
+  detail::FieldInfo secondInfo(second.type());
   return detail::compareFieldSortOrder(firstInfo, secondInfo);
 }