--- ./histlib.h	2016-04-22 15:03:20.000000000 +0000
+++ ../histlib.h	2018-03-18 19:50:23.834494092 +0000
@@ -52,7 +52,7 @@
 
 #ifndef member
 #  ifndef strchr
-extern char *strchr ();
+extern char __attribute__((overloadable)) *strchr ();
 #  endif
 #define member(c, s) ((c) ? ((char *)strchr ((s), (c)) != (char *)NULL) : 0)
 #endif