diff --git a/Lib/urllib2.py b/Lib/urllib2.py
index df3729a..7124dfb 100644
--- a/Lib/urllib2.py
+++ b/Lib/urllib2.py
@@ -145,8 +145,12 @@
 
 class URLError(IOError):
     # URLError is a sub-type of IOError, but it doesn't share any of
-    # the implementation.  need to override __init__ and __str__
+    # the implementation.  need to override __init__ and __str__.
+    # It sets self.args for compatibility with other EnvironmentError
+    # subclasses, but args doesn't have the typical format with errno in
+    # slot 0 and strerror in slot 1.  This may be better than nothing.
     def __init__(self, reason):
+        self.args = reason,
         self.reason = reason
 
     def __str__(self):