diff --git a/mercurial_keyring.py b/mercurial_keyring.py
--- a/mercurial_keyring.py
+++ b/mercurial_keyring.py
@@ -303,9 +303,13 @@ class HTTPPasswordHandler(object):
             return url_user, url_passwd, self.SRC_URL, base_url
 
         # Extract data from urllib (in case it was already stored)
-        urllib_user, urllib_pwd \
-            = urllib2.HTTPPasswordMgrWithDefaultRealm.find_user_password(
-                pwmgr, realm, authuri)
+        if isinstance(pwmgr, urllib2.HTTPPasswordMgrWithDefaultRealm):
+            urllib_user, urllib_pwd = \
+                urllib2.HTTPPasswordMgrWithDefaultRealm.find_user_password(
+                    pwmgr, realm, authuri)
+        else:
+            urllib_user, urllib_pwd = pwmgr.passwddb.find_user_password(
+                realm, authuri)
         if urllib_user and urllib_pwd:
             return urllib_user, urllib_pwd, self.SRC_URLCACHE, base_url