diff -Naur a/configure.ac b/configure.ac
--- a/configure.ac	2008-04-23 20:37:42.000000000 +0900
+++ b/configure.ac	2021-05-16 01:28:24.000000000 +0900
@@ -46,9 +46,7 @@
 
 # Checks for library functions.
 AC_FUNC_CHOWN
-AC_FUNC_MALLOC
 AC_FUNC_MKTIME
-AC_FUNC_REALLOC
 AC_FUNC_SELECT_ARGTYPES
 AC_FUNC_STRFTIME
 AC_FUNC_UTIME_NULL