diff --git a/ChangeLog b/ChangeLog
index e5d8a1bbf1..2f66312628 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Fri May  3 20:19:00 2002  WATANABE Hirofumi  <eban@ruby-lang.org>
+
+	* configure.in: add #include <errno.h> in AC_CHECK_DECLS().
+
 Thu May  2 18:27:13 2002  WATANABE Hirofumi  <eban@ruby-lang.org>
 
 	* ext/extmk.rb.in, lib/mkmf.rb: use 'do...end' instead of '{}' for
diff --git a/configure.in b/configure.in
index 0785fef1bb..3c6a7c4dfd 100644
--- a/configure.in
+++ b/configure.in
@@ -187,7 +187,8 @@ done])
 AC_DEFINE_UNQUOTED([NORETURN(x)], $rb_cv_noreturn)
 
 dnl Check whether we need to define sys_nerr locally
-AC_CHECK_DECLS([sys_nerr])
+AC_CHECK_DECLS([sys_nerr], [], [], [$ac_includes_default
+#include <errno.h>])
 
 dnl whether link libc_r or not
 AC_ARG_WITH(libc_r,