Index: lib/net/ftp.rb
===================================================================
--- lib/net/ftp.rb	(Revision 18315)
+++ lib/net/ftp.rb	(Arbeitskopie)
@@ -668,9 +668,9 @@
 	begin
 	  voidcmd("CDUP")
 	  return
-	rescue FTPPermError
-	  if $![0, 3] != "500"
-	    raise FTPPermError, $!
+	rescue FTPPermError => e
+	  if e.message[0, 3] != "500"
+	    raise e
 	  end
 	end
       end