diff --git a/modules/src/string/btszero.c b/modules/src/string/btszero.c
index e36074a97..dfdfcb650 100644
--- a/modules/src/string/btszero.c
+++ b/modules/src/string/btszero.c
@@ -8,9 +8,13 @@
 
 char *
 btszero(b, n)
-	register char *b;
+	char *b;
 	register int n;
 {
+	register char *s = b;
+
 	while (n-- > 0)
-		*b++ = '\0';
+		*s++ = '\0';
+	
+	return b;
 }
diff --git a/modules/src/string/strzero.c b/modules/src/string/strzero.c
index a9bbed1a4..f122cc579 100644
--- a/modules/src/string/strzero.c
+++ b/modules/src/string/strzero.c
@@ -11,4 +11,5 @@ strzero(s)
 	char *s;
 {
 	*s = '\0';
+	return s;
 }