diff --git a/ndn-cpp/transport/transport.cpp b/ndn-cpp/transport/transport.cpp
index 4b8aca1..b36b119 100644
--- a/ndn-cpp/transport/transport.cpp
+++ b/ndn-cpp/transport/transport.cpp
@@ -22,7 +22,7 @@
 }
   
 void 
-Transport::send(const uint8_t *data, unsigned int dataLength)
+Transport::send(const uint8_t *data, size_t dataLength)
 {
   throw logic_error("unimplemented");
 }