Changing Class attribute from octets to string

Hello, I need to use the class attribute in order to assign the user to a service plan in a DPI box. The Class attribute is been carried in the acct packets, the problem is that Freeradius is converting it to hexadecimal, I've changed the type from octets to string and restarted the service but it continued to be converted to hex. What can I do to get this attribute to be carried in plain text format? Thanks. --