prog_char not declared in the T6963 library

I have a CrystalFontz 240128 display working with u8glib on a mega, and I am trying to get it to work with the T6963 library as the u8glib is slow and I am mainly updating a few characters on each iteration of the loop. However, when I attempt to compile the helloworld.ino sample from the T6963 library I get the compile error below:

Arduino: 1.7.10 (Windows 8.1), Board: "Arduino Mega or Mega 2560, ATmega2560 (Mega 2560)"

In file included from T6963_helloworld.ino:3:0:

C:\Program Files (x86)\Arduino\libraries\T6963/T6963.h:108:23: error: 'prog_char' has not been declared

void WriteStringPgm(prog_char * str);

^

In file included from C:\Program Files (x86)\Arduino\libraries\T6963/gfxdata.h:12:0,

from T6963_helloworld.ino:2:

etc.

I did a search and found this problem has come up before, and a proposed solution was to define a compatibility mode using #define PROG_TYPES_COMPAT

So I attempted that solution by adding the #define before the include "avr/pgmspace.h" but that makes no difference. Anyone have any ideas?