diff --git a/boot/fat.asm b/boot/fat.asm
index 1a422b3..e6b2a57 100644
--- a/boot/fat.asm
+++ b/boot/fat.asm
@@ -112,7 +112,7 @@ offset_fat:	; add reserved sectors
 		adc dx, 0
 offset_part:	; add partition offset
 		add ax, [bp+BPBHS]
-		add dx, [bp+BPBHS]
+		add dx, [bp+BPBHS+2]
 		ret
 
 resetbuf:	; DS = ES