How to change the include file path with autotools

Question

I am developing a simple chat application, which use crypto++, in ubuntu. The folder for crypto++'s header files is /usr/include/crypto++/.

After I upload the source tagbar to CentOS, I found that the folder for crypto++'s header files is /usr/include/cryptopp. So in CentOS, the compiler could not find the head files for cryptopp.

Source File:

#include "crypto++/md5.h"

Configure.ac:

AC_SEARCH_LIBS([_ZTIN8CryptoPP14CBC_EncryptionE], [crypto++ cryptopp], 
        [],[AC_MSG_ERROR([avchat requires crypto++/cryptopp])])

How to make the source bundle portable both on ubuntu and centos?