diff --git a/mach/pdp/libem/mlu4.s b/mach/pdp/libem/mlu4.s
index cc312ca22..798bbaa63 100644
--- a/mach/pdp/libem/mlu4.s
+++ b/mach/pdp/libem/mlu4.s
@@ -5,20 +5,18 @@
 
 mlu4~:
 	jsr	pc,save~
-	clr	r0
-	mov	02(sp),r1
+	clr	r1
+	mov	02(sp),r0
 	mov	06(sp),r3
 	mul	r3,r0
 	tst	r3
 	bge	1f
-	ashc	$15.,r0
+	add	02(sp),r0
 1:	mov	02(sp),r3
-	clr	r2
-	mul	04(sp),r2
+	mul	04(sp),r3
 	add	r3,r0
 	mov	06(sp),r3
-	clr	r2
-	mul	(sp),r2
+	mul	(sp),r3
 	add	r3,r0
 	add	$010,sp
 	jmp	retu~