diff --git a/ChangeLog b/ChangeLog
index 528c7aa5ba..c13417d516 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,10 +1,14 @@
+Mon Sep 19 18:58:10 2005  Minero Aoki  <aamine@loveruby.net>
+
+	* file.c (rb_file_chown): should accept nil. [ruby-dev:27171]
+
 Mon Sep 19 15:12:15 2005  Minero Aoki  <aamine@loveruby.net>
 
 	* ext/ripper/depend: do not make ripper/core.rb. [ruby-dev:26462]
 
 Mon Sep 19 14:49:19 2005  Minero Aoki  <aamine@loveruby.net>
 
-	* ext/ripper/eventids2.c: add prefix `t' to lambda related lexer
+	* ext/ripper/eventids2.c: add prefix `t' to tLAMBDA-related lexer
 	  events.
 
 	* ext/ripper/lib/ripper/core.rb: updated.
diff --git a/file.c b/file.c
index 740ec77bda..6302bb8935 100644
--- a/file.c
+++ b/file.c
@@ -1745,8 +1745,8 @@ rb_file_chown(VALUE obj, VALUE owner, VALUE group)
     int o, g;
 
     rb_secure(2);
-    o = NUM2INT(owner);
-    g = NUM2INT(group);
+    o = NIL_P(owner) ? -1 : NUM2INT(owner);
+    g = NIL_P(group) ? -1 : NUM2INT(group);
     GetOpenFile(obj, fptr);
 #if defined(DJGPP) || defined(__CYGWIN32__) || defined(_WIN32) || defined(__EMX__)
     if (!fptr->path) return Qnil;