diff --git a/ChangeLog b/ChangeLog
index 8991e0833a..9f34cd99bc 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Thu Jun 22 11:52:02 2006  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* lib/net/http.rb (Net::HTTPResponse): duplicated error 501;
+	  HTTPInternalServerError should be error 500.  [ruby-core:08037]
+
 Thu Jun 22 11:47:52 2006  Yukihiro Matsumoto  <matz@ruby-lang.org>
 
 	* variable.c (rb_mod_name): returns nil for anonymous modules.
diff --git a/lib/net/http.rb b/lib/net/http.rb
index 87f42bfb66..f6e8e9dce3 100644
--- a/lib/net/http.rb
+++ b/lib/net/http.rb
@@ -1962,7 +1962,7 @@ module Net   #:nodoc:
       '416' => HTTPRequestedRangeNotSatisfiable,
       '417' => HTTPExpectationFailed,
 
-      '501' => HTTPInternalServerError,
+      '500' => HTTPInternalServerError,
       '501' => HTTPNotImplemented,
       '502' => HTTPBadGateway,
       '503' => HTTPServiceUnavailable,