diff --git a/ChangeLog b/ChangeLog
index e21ad9e894..924430a590 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Mon Aug  9 06:52:59 2010  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* dir.c (sys_warning_1): show error message.
+
 Mon Aug  9 06:50:28 2010  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* test/ruby/test_require.rb (test_require_too_long_filename):
diff --git a/dir.c b/dir.c
index 5c972898de..483c8beafc 100644
--- a/dir.c
+++ b/dir.c
@@ -992,7 +992,7 @@ dir_s_rmdir(VALUE obj, VALUE dir)
 static VALUE
 sys_warning_1(VALUE mesg)
 {
-    rb_sys_warning("%s", (const char *)mesg);
+    rb_sys_warning("%s:%s", strerror(errno), (const char *)mesg);
     return Qnil;
 }