diff --git a/ChangeLog b/ChangeLog
index 62b1af97ef..08184fa36c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sun Feb  9 08:34:45 2003  Minero Aoki  <aamine@loveruby.net>
+
+	* lib/net/http.rb: 4xx raises Net::ProtoServerError, 5xx raises
+	  Net::ProtoFatalError (for backward compatibility).
+
 Sun Feb  9 07:07:26 2003  Minero Aoki  <aamine@loveruby.net>
 
 	* lib/fileutils.rb: new method FileUtils.pwd (really).
diff --git a/lib/net/http.rb b/lib/net/http.rb
index 82274b11dd..f5b70188db 100644
--- a/lib/net/http.rb
+++ b/lib/net/http.rb
@@ -1257,11 +1257,11 @@ module Net
   end
   class HTTPClientError < HTTPResponse           # 4xx
     HAS_BODY = true
-    EXCEPTION_TYPE = ProtoFatalError
+    EXCEPTION_TYPE = ProtoServerError   # for backward compatibility
   end
   class HTTPServerError < HTTPResponse           # 5xx
     HAS_BODY = true
-    EXCEPTION_TYPE = ProtoServerError
+    EXCEPTION_TYPE = ProtoFatalError    # for backward compatibility
   end
 
   class HTTPContinue < HTTPInformation           # 100