diff --git a/mercurial_keyring.py b/mercurial_keyring.py
--- a/mercurial_keyring.py
+++ b/mercurial_keyring.py
@@ -120,7 +120,7 @@ class HTTPPasswordHandler(object):
 
         # Loading .hg/hgrc [auth] section contents. If prefix is given,
         # it will be used as a key to lookup password in the keyring.
-        auth_user, pwd, prefix_url = self.load_hgrc_auth(ui, base_url)
+        auth_user, pwd, prefix_url = self.load_hgrc_auth(ui, base_url, user)
         if prefix_url:
             keyring_url = prefix_url
         else:
@@ -197,7 +197,7 @@ class HTTPPasswordHandler(object):
         self.last_reply = dict(realm=realm,authuri=authuri,user=user)
         return user, pwd
 
-    def load_hgrc_auth(self, ui, base_url):
+    def load_hgrc_auth(self, ui, base_url, user):
         """
         Loading [auth] section contents from local .hgrc
 
@@ -241,7 +241,11 @@ class HTTPPasswordHandler(object):
                 # hg 1.9
                 import mercurial.httpconnection
                 readauthforuri = mercurial.httpconnection.readauthforuri
-            res = readauthforuri(local_ui, base_url)
+            if readauthforuri.func_code.co_argcount == 3:
+                # Since hg.0593e8f81c71
+                res = readauthforuri(local_ui, base_url, user)
+            else:
+                res = readauthforuri(local_ui, base_url)
             if res:
                 group, auth_token = res
             else: