diff --git a/ndn-cpp/common.hpp b/ndn-cpp/common.hpp
index ebf6992..4e451a9 100644
--- a/ndn-cpp/common.hpp
+++ b/ndn-cpp/common.hpp
@@ -56,7 +56,8 @@
  * @param array The array of bytes.
  * @return Hex string.
  */
-std::string toHex(const std::vector<unsigned char>& array);
+std::string 
+toHex(const std::vector<unsigned char>& array);
 
 }