diff --git a/bin/sh/expand.c b/bin/sh/expand.c
index 3b6a45d08818..af88771babe1 100644
--- a/bin/sh/expand.c
+++ b/bin/sh/expand.c
@@ -145,10 +145,12 @@ appendarglist(struct arglist *list, char *str)
 static int
 collate_range_cmp(wchar_t c1, wchar_t c2)
 {
-	static wchar_t s1[2], s2[2];
+	wchar_t s1[2], s2[2];
 
 	s1[0] = c1;
+	s1[1] = L'\0';
 	s2[0] = c2;
+	s2[1] = L'\0';
 	return (wcscoll(s1, s2));
 }