diff --git a/apps/lib/util.asm b/apps/lib/util.asm
index 3010ed6..df04d4f 100644
--- a/apps/lib/util.asm
+++ b/apps/lib/util.asm
@@ -80,16 +80,16 @@ strcmp:
 ; Given a string at (HL), move HL until it points to the end of that string.
 strskip:
 	push	bc
-	ld	b, a
+	ex	af, af'
 	xor	a	; look for null char
+	ld	b, a
 	ld	c, a
 	cpir	; advances HL regardless of comparison, so goes one too far
 	dec	hl
-	ld	a, b
+	ex	af, af'
 	pop	bc
 	ret
 
-
 ; Returns length of string at (HL) in A.
 ; Doesn't include null termination.
 strlen: