diff --git a/asminc/rp6502.inc b/asminc/rp6502.inc
index 7dd1b8fcd..816712abb 100644
--- a/asminc/rp6502.inc
+++ b/asminc/rp6502.inc
@@ -37,6 +37,7 @@ RIA_OP_PHI2               := $02
 RIA_OP_CODEPAGE           := $03
 RIA_OP_LRAND              := $04
 RIA_OP_STDIN_OPT          := $05
+RIA_OP_CLOCK              := $0F
 RIA_OP_CLOCK_GETRES       := $10
 RIA_OP_CLOCK_GETTIME      := $11
 RIA_OP_CLOCK_SETTIME      := $12