diff --git a/ndn-cpp/transport/tcp-transport.hpp b/ndn-cpp/transport/tcp-transport.hpp
index d999df8..594f007 100644
--- a/ndn-cpp/transport/tcp-transport.hpp
+++ b/ndn-cpp/transport/tcp-transport.hpp
@@ -72,7 +72,7 @@
    * @param data A pointer to the buffer of data to send.
    * @param dataLength The number of bytes in data.
    */
-  virtual void send(const uint8_t *data, unsigned int dataLength);
+  virtual void send(const uint8_t *data, size_t dataLength);
 
   /**
    * Process any data to receive.  For each element received, call elementListener.onReceivedElement.