diff --git a/sys/dev/buslogic/btreg.h b/sys/dev/buslogic/btreg.h
index 61491c6275f..4a796f2a581 100644
--- a/sys/dev/buslogic/btreg.h
+++ b/sys/dev/buslogic/btreg.h
@@ -112,7 +112,7 @@ typedef enum {
 #define GEOMETRY_REG			0x03
 #define		DISK0_GEOMETRY		0x03
 #define		DISK1_GEOMETRY		0x0c
-#define		EXTENDED_TRANSLATION	0x10
+#define		EXTENDED_TRANSLATION	0x80
 #define		GEOMETRY_DISK0(g_reg) (greg & DISK0_GEOMETRY)
 #define		GEOMETRY_DISK1(g_reg) ((greg & DISK1_GEOMETRY) >> 2)