diff --git a/ndn-cpp/node.hpp b/ndn-cpp/node.hpp
index eba6eb5..a9bd81f 100644
--- a/ndn-cpp/node.hpp
+++ b/ndn-cpp/node.hpp
@@ -90,7 +90,7 @@
   getConnectionInfo() { return connectionInfo_; }
 
   void 
-  onReceivedElement(const uint8_t *element, unsigned int elementLength);
+  onReceivedElement(const uint8_t *element, size_t elementLength);
   
   void 
   shutdown();