Index: configure.in
--- configure.in.orig
+++ configure.in
@@ -52,7 +52,7 @@ touch confdefs.h
 AC_TRY_RUN([#include <stdlib.h>
 #include "confdefs.h"
 long random() { return 1; }
-main() { exit(0); }
+int main(void) { exit(0); }
 ],
 AC_MSG_RESULT(long)
 AC_DEFINE(RANDOM_RETURN_TYPE,long)
