--- a/m4/strftime.m4
+++ b/m4/strftime.m4
@@ -1,25 +1,23 @@
-#serial 18
+#serial 19
 
 dnl This macro is intended to be used solely in this file.
 dnl These are the prerequisite macros for GNU's strftime.c replacement.
 AC_DEFUN([_jm_STRFTIME_PREREQS],
 [
  dnl strftime.c uses the underyling system strftime if it exists.
- AC_CHECK_FUNCS(strftime)
+ AC_FUNC_STRFTIME
 
- AC_CHECK_HEADERS(limits.h)
- AC_CHECK_FUNCS(bcopy tzset mempcpy memcpy memset)
+ AC_CHECK_HEADERS_ONCE(limits.h)
+ AC_CHECK_FUNCS_ONCE(memcpy mempcpy)
+ AC_CHECK_FUNCS(tzset memset)
 
  # This defines (or not) HAVE_TZNAME and HAVE_TM_ZONE.
  AC_STRUCT_TIMEZONE
 
  AC_CHECK_FUNCS(mblen mbrlen)
+ AC_TYPE_MBSTATE_T
 
- AC_CHECK_MEMBER([struct tm.tm_gmtoff],
-                 [AC_DEFINE(HAVE_TM_GMTOFF, 1,
-                            [Define if struct tm has the tm_gmtoff member.])],
-                 ,
-                 [#include <time.h>])
+ AC_REQUIRE([gl_TM_GMTOFF])
 ])
 
 dnl From Jim Meyering.
@@ -31,7 +29,7 @@
 
  AC_REQUIRE([AC_C_CONST])dnl
  AC_REQUIRE([AC_HEADER_STDC])dnl
- AC_CHECK_HEADERS(sys/time.h)
+ AC_CHECK_HEADERS_ONCE(sys/time.h)
  AC_DEFINE([my_strftime], [nstrftime],
    [Define to the name of the strftime replacement function.])
 ])