diff --git a/sys/dev/disk/advansys/adwlib.h b/sys/dev/disk/advansys/adwlib.h
--- a/sys/dev/disk/advansys/adwlib.h
+++ b/sys/dev/disk/advansys/adwlib.h
@@ -61,7 +61,7 @@
 
 #define	ADW_ALL_TARGETS		0xFFFF
 
-#define ADW_TARGET_GROUP(tid)		((tid) & ~0x3)
+#define ADW_TARGET_GROUP(tid)		((tid) >> 2)
 #define ADW_TARGET_GROUP_SHIFT(tid)	(((tid) & 0x3) * 4)
 #define ADW_TARGET_GROUP_MASK(tid)	(0xF << ADW_TARGET_GROUP_SHIFT(tid))