1diff --git histlib.h histlib.h
2index c938a10..925ab72 100644
3--- histlib.h
4+++ histlib.h
5@@ -51,9 +51,9 @@
6 #endif
7
8 #ifndef member
9-# ifndef strchr
10+# if !defined (strchr) && !defined (__STDC__)
11 extern char *strchr ();
12-# endif
13+# endif /* !strchr && !__STDC__ */
14 #define member(c, s) ((c) ? ((char *)strchr ((s), (c)) != (char *)NULL) : 0)
15 #endif
16