diff --git a/lib/openid/yadis/xrires.rb b/lib/openid/yadis/xrires.rb
index 233826b1..c9cf6e6c 100644
--- a/lib/openid/yadis/xrires.rb
+++ b/lib/openid/yadis/xrires.rb
@@ -13,7 +13,7 @@ class XRIHTTPError < StandardError; end
 
       class ProxyResolver
 
-        DEFAULT_PROXY ||= 'http://proxy.xri.net/'
+        DEFAULT_PROXY = 'http://proxy.xri.net/' unless defined?(DEFAULT_PROXY)
 
         def initialize(proxy_url=nil)
           if proxy_url