diff --git a/mach/vax4/libem/cuu.s b/mach/vax4/libem/cuu.s
index 14931e22a..efafd2aa9 100644
--- a/mach/vax4/libem/cuu.s
+++ b/mach/vax4/libem/cuu.s
@@ -6,20 +6,11 @@
 
 .cuu:
 	movl    (sp)+,r1
-	movl    (sp)+,r0
-	cmpl    (sp),$1
-	beql    Lfrom1
-	cmpl    (sp),$2
-	beql    Lfrom2
+	cmpl	(sp)+,$4
+	bneq	Lerr
 	cmpl	(sp)+, $4
 	bneq	Lerr
 	jmp     (r1)
-Lfrom1:
-	movzbw	4(sp), 4(sp)
-Lfrom2:
-	tstl	(sp)+
-	movzwl	(sp), (sp)
-	jmp	(r1)
 Lerr:
 	pushl	$EILLINS
 	jmp     .fat