diff --git a/libsrc/runtime/add.s b/libsrc/runtime/add.s
index 5d83ef9a2..49c7eca96 100644
--- a/libsrc/runtime/add.s
+++ b/libsrc/runtime/add.s
@@ -8,7 +8,7 @@
 ; called a lot!
 
        	.export		tosadda0, tosaddax
-	.importzp	sp, tmp1
+	.importzp	sp
 
 tosadda0:
 	ldx	#0
@@ -16,7 +16,7 @@ tosaddax:
 	ldy	#0
 	clc
 	adc	(sp),y		; lo byte
-	sta	tmp1		; save it
+       	pha			; save it
 	txa
 	iny
 	adc	(sp),y		; hi byte
@@ -27,21 +27,6 @@ tosaddax:
 	sta	sp
 	bcc	L1
 	inc	sp+1
-L1:	txa	    		; Test high byte
-	bmi	L2
-	bne	L3
-	lda	tmp1		; Get low byte
-	rts
-
-; Value is negative
-
-L2:	lda	tmp1		; Get low byte
-	ldy	#$FF		; Force negative
-	rts
-
-; Value is positive != 0
-
-L3:	lda	tmp1		; Get low byte
-	ldy	#1
+L1:    	pla			; Restore low byte
 	rts