diff --git a/devstack/lib/magnum b/devstack/lib/magnum
index 964e87cae1..1af8755d34 100644
--- a/devstack/lib/magnum
+++ b/devstack/lib/magnum
@@ -160,7 +160,7 @@ function create_magnum_conf {
     configure_auth_token_middleware $MAGNUM_CONF magnum $MAGNUM_AUTH_CACHE_DIR
 
     iniset $MAGNUM_CONF keystone_auth auth_url $KEYSTONE_AUTH_URI_V3
-    iniset $MAGNUM_CONF keystone_authtoken auth_uri $KEYSTONE_SERVICE_URI_V3
+    iniset $MAGNUM_CONF keystone_authtoken www_authenticate_uri $KEYSTONE_SERVICE_URI_V3
     iniset $MAGNUM_CONF keystone_authtoken auth_url $KEYSTONE_AUTH_URI_V3
     iniset $MAGNUM_CONF keystone_authtoken auth_version v3
 
diff --git a/magnum/common/keystone.py b/magnum/common/keystone.py
index 44bf38f827..59ac8be972 100755
--- a/magnum/common/keystone.py
+++ b/magnum/common/keystone.py
@@ -44,7 +44,12 @@ class KeystoneClientV3(object):
     def auth_url(self):
         # FIXME(pauloewerton): auth_url should be retrieved from keystone_auth
         # section by default
-        return CONF[ksconf.CFG_LEGACY_GROUP].auth_uri.replace('v2.0', 'v3')
+        conf = CONF[ksconf.CFG_LEGACY_GROUP]
+        auth_uri = (getattr(conf, 'www_authenticate_uri', None) or
+                    getattr(conf, 'auth_uri', None))
+        if auth_uri:
+            auth_uri = auth_uri.replace('v2.0', 'v3')
+        return auth_uri
 
     @property
     def auth_token(self):
diff --git a/magnum/tests/contrib/post_test_hook.sh b/magnum/tests/contrib/post_test_hook.sh
index 92b88880f2..dd53fe327c 100755
--- a/magnum/tests/contrib/post_test_hook.sh
+++ b/magnum/tests/contrib/post_test_hook.sh
@@ -68,7 +68,7 @@ function create_test_data {
     local magnum_api_ip=$(iniget /etc/magnum/magnum.conf api host)
     local magnum_api_port=$(iniget /etc/magnum/magnum.conf api port)
     local magnum_url="http://"$magnum_api_ip":"$magnum_api_port"/v1"
-    local keystone_auth_url=$(iniget /etc/magnum/magnum.conf keystone_authtoken auth_uri)
+    local keystone_auth_url=$(iniget /etc/magnum/magnum.conf keystone_authtoken www_authenticate_uri)
 
     # pass the appropriate variables via a config file
     CREDS_FILE=$MAGNUM_DIR/functional_creds.conf