diff --git a/ndn-cpp/transport/tcp-transport.cpp b/ndn-cpp/transport/tcp-transport.cpp
index 553c5c7..9a712fb 100644
--- a/ndn-cpp/transport/tcp-transport.cpp
+++ b/ndn-cpp/transport/tcp-transport.cpp
@@ -27,7 +27,7 @@
     throw std::runtime_error(ndn_getErrorString(error)); 
 
   // TODO: This belongs in the socket listener.
-  const unsigned int initialLength = 1000;
+  const size_t initialLength = 1000;
   // Automatically cast elementReader_ to (struct ndn_ElementListener *)
   ndn_BinaryXmlElementReader_initialize
     (&elementReader_, &elementListener, (uint8_t *)malloc(initialLength), initialLength, ndn_realloc);
@@ -37,7 +37,7 @@
 }
 
 void 
-TcpTransport::send(const uint8_t *data, unsigned int dataLength)
+TcpTransport::send(const uint8_t *data, size_t dataLength)
 {
   ndn_Error error;
   if ((error = ndn_TcpTransport_send(&transport_, (uint8_t *)data, dataLength)))
@@ -55,7 +55,7 @@
     return;
 
   uint8_t buffer[8000];
-  unsigned int nBytes;
+  size_t nBytes;
   if ((error = ndn_TcpTransport_receive(&transport_, buffer, sizeof(buffer), &nBytes)))
     throw std::runtime_error(ndn_getErrorString(error));  
 
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.
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");
 }
diff --git a/ndn-cpp/transport/transport.hpp b/ndn-cpp/transport/transport.hpp
index ed3e240..512a003 100644
--- a/ndn-cpp/transport/transport.hpp
+++ b/ndn-cpp/transport/transport.hpp
@@ -37,7 +37,7 @@
    * @param dataLength The number of bytes in data.
    */
   virtual void 
-  send(const uint8_t *data, unsigned int dataLength);
+  send(const uint8_t *data, size_t dataLength);
   
   void 
   send(const std::vector<uint8_t>& data)
diff --git a/ndn-cpp/transport/udp-transport.cpp b/ndn-cpp/transport/udp-transport.cpp
index 0b2f397..4e65375 100644
--- a/ndn-cpp/transport/udp-transport.cpp
+++ b/ndn-cpp/transport/udp-transport.cpp
@@ -27,7 +27,7 @@
     throw std::runtime_error(ndn_getErrorString(error)); 
 
   // TODO: This belongs in the socket listener.
-  const unsigned int initialLength = 1000;
+  const size_t initialLength = 1000;
   // Automatically cast elementReader_ to (struct ndn_ElementListener *)
   ndn_BinaryXmlElementReader_initialize
     (&elementReader_, &elementListener, (uint8_t *)malloc(initialLength), initialLength, ndn_realloc);
@@ -37,7 +37,7 @@
 }
 
 void 
-UdpTransport::send(const uint8_t *data, unsigned int dataLength)
+UdpTransport::send(const uint8_t *data, size_t dataLength)
 {
   ndn_Error error;
   if ((error = ndn_UdpTransport_send(&transport_, (uint8_t *)data, dataLength)))
@@ -55,7 +55,7 @@
     return;
 
   uint8_t buffer[8000];
-  unsigned int nBytes;
+  size_t nBytes;
   if ((error = ndn_UdpTransport_receive(&transport_, buffer, sizeof(buffer), &nBytes)))
     throw std::runtime_error(ndn_getErrorString(error));  
 
diff --git a/ndn-cpp/transport/udp-transport.hpp b/ndn-cpp/transport/udp-transport.hpp
index b2374df..633b9ad 100644
--- a/ndn-cpp/transport/udp-transport.hpp
+++ b/ndn-cpp/transport/udp-transport.hpp
@@ -74,7 +74,7 @@
    * @param dataLength The number of bytes in data.
    */
   virtual void 
-  send(const uint8_t *data, unsigned int dataLength);
+  send(const uint8_t *data, size_t dataLength);
 
   /**
    * Process any data to receive.  For each element received, call elementListener.onReceivedElement.