diff --git a/constants/dss_equ.inc b/constants/dss_equ.inc
index f644d97..1a2ba9b 100644
--- a/constants/dss_equ.inc
+++ b/constants/dss_equ.inc
@@ -166,6 +166,9 @@ Dss:
  ;.DRV.Reserved	EQU	#09
 .DRV.LongRead	EQU	#10
 .DRV.LongWrite	EQU	#11
+;
+.DRV.RescanDRV	EQU	#FF
+;---------------------------------------