diff --git a/mach/i86/libem/sti.s b/mach/i86/libem/sti.s
index 296b70545..097580b8e 100644
--- a/mach/i86/libem/sti.s
+++ b/mach/i86/libem/sti.s
@@ -17,10 +17,10 @@
 	mov	di,dx
 	jmp     bx
 1:
-	mov	bx,si
+	mov	ax,si
 	mov     si,sp
 	rep movs
 	mov     sp,si
 	mov	di,dx
-	mov	si,bx
+	mov	si,ax
 	jmp     bx