diff --git a/ndn-cpp/encoding/binary-xml-decoder.hpp b/ndn-cpp/encoding/binary-xml-decoder.hpp
index 1bbca34..f75d4f0 100644
--- a/ndn-cpp/encoding/binary-xml-decoder.hpp
+++ b/ndn-cpp/encoding/binary-xml-decoder.hpp
@@ -22,7 +22,7 @@
   /**
    * Initialize the base ndn_BinaryXmlDecoder struct with the input.
    */
-  BinaryXmlDecoder(const uint8_t *input, unsigned int inputLength) 
+  BinaryXmlDecoder(const uint8_t *input, size_t inputLength) 
   {
     ndn_BinaryXmlDecoder_initialize(this, (uint8_t *)input, inputLength);
   }