--- a/defines.s
+++ b/defines.s
@@ -24,6 +24,9 @@
 .elseif .def(aim65)
 AIM65 := 1
 .include "defines_aim65.s"
+.elseif .def(rk65c02)
+RK65C02 := 1
+.include "defines_rk65c02.s"
 .elseif .def(sym1)
 SYM1 := 1
 .include "defines_sym1.s"