diff --git a/ChangeLog b/ChangeLog
index ba7bdba62f..298e4b94b5 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Wed Apr  9 15:35:04 2003  NAKAMURA Usaku <usa@ruby-lang.org>
+
+	* ext/readline/readline.c: include <unistd.h> only when
+	  HAVE_UNISTD_H is defined.
+
 Wed Apr  9 14:05:00 2003  Nobuyoshi Nakada  <nobu.nokada@softhome.net>
 
 	* marshal.c (w_object): preserve extended module on struct.
diff --git a/ext/readline/readline.c b/ext/readline/readline.c
index fc17dad4f1..bc98df92f6 100644
--- a/ext/readline/readline.c
+++ b/ext/readline/readline.c
@@ -3,7 +3,9 @@
 
 #include <errno.h>
 #include <stdio.h>
+#ifdef HAVE_UNISTD_H
 #include <unistd.h>
+#endif
 #include <readline/readline.h>
 #include <readline/history.h>