Compiler/TMS320F28379D: printf 'z' specifier doesn't work with size_t

Tool/software: TI C/C++ Compiler

The following code outputs a 'u' instead of the correct size:

size_t numOctets = (sizeof(MACAddress)/sizeof(uint16_t));
printf("numOctets = %zu\n", numOctets);

I believe this is the correct method to output a size_t type via printf.

Kindly,

Graham