diff --git a/ChangeLog b/ChangeLog
index dbcaab7199..dbbf53c9ba 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Fri Jul  9 19:26:39 2004  Tanaka Akira  <akr@m17n.org>
+
+	* lib/open-uri.rb (URI::HTTPS#proxy_open): raise ArgumentError to
+	  notice https is not supported.
+
 Fri Jul  9 14:28:54 2004  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* eval.c (rb_thread_raise): accept third argument as well as
diff --git a/lib/open-uri.rb b/lib/open-uri.rb
index a6186fbb2c..8d0353bbc9 100644
--- a/lib/open-uri.rb
+++ b/lib/open-uri.rb
@@ -578,6 +578,12 @@ module URI
     include OpenURI::OpenRead
   end
 
+  class HTTPS
+    def proxy_open(buf, uri, options) # :nodoc:
+      raise ArgumentError, "open-uri doesn't support https."
+    end
+  end
+
   class FTP
     def direct_open(buf, options) # :nodoc:
       require 'net/ftp'