AC_CHECK_SIZEOF([long])
# Checks for library functions.
-AC_CHECK_FUNCS([strchr strdup strstr timegm strcasecmp])
+AC_CHECK_FUNCS([strchr strdup strstr timegm gmtime_r strcasecmp])
AC_CHECK_HEADERS([dlfcn.h])
AC_CHECK_FUNC(dlclose, , [ AC_CHECK_LIB(dl, dlopen) ])