diff --git a/sys/i386/i386/exception.s b/sys/i386/i386/exception.s
index 2373fa425210..ab6c83843bfe 100644
--- a/sys/i386/i386/exception.s
+++ b/sys/i386/i386/exception.s
@@ -530,7 +530,7 @@ doreti_exit:
 	testl	$PSL_VM,TF_EFLAGS(%esp)
 	jz	2f			/* PCB_VM86CALL is not set */
 	addl	$VM86_STACK_SPACE, %ecx
-2:	subl	$TF_SZ, %edx
+2:	subl	%ecx, %edx
 	movl	%edx, %edi
 	rep; movsb
 	movl	%edx, %esp