diff --git a/cms/envs/common.py b/cms/envs/common.py
index 5af3d7ab9b..e3e0dcfb6c 100644
--- a/cms/envs/common.py
+++ b/cms/envs/common.py
@@ -652,8 +652,9 @@ LOGIN_REDIRECT_URL = EDX_ROOT_URL + '/home/'
 LOGIN_URL = reverse_lazy('login_redirect_to_lms')
 FRONTEND_LOGIN_URL = lambda settings: settings.LMS_ROOT_URL + '/login'
 derived('FRONTEND_LOGIN_URL')
-FRONTEND_LOGOUT_URL = lambda settings: settings.LMS_ROOT_URL + '/logout'
-derived('FRONTEND_LOGOUT_URL')
+# Warning: Must have trailing slash to activate correct logout view
+# (auth_backends, not LMS user_authn)
+FRONTEND_LOGOUT_URL = '/logout/'
 FRONTEND_REGISTER_URL = lambda settings: settings.LMS_ROOT_URL + '/register'
 derived('FRONTEND_REGISTER_URL')
 
diff --git a/cms/envs/devstack.py b/cms/envs/devstack.py
index 70b966a8b9..1bfc970beb 100644
--- a/cms/envs/devstack.py
+++ b/cms/envs/devstack.py
@@ -51,7 +51,6 @@ FEATURES['PREVIEW_LMS_BASE'] = "preview." + LMS_BASE
 # TODO: Remove after Studio OAuth transition is complete. See docs/guides/studio_oauth.rst
 LOGIN_URL = '/login/'
 FRONTEND_LOGIN_URL = LMS_ROOT_URL + '/login'
-FRONTEND_LOGOUT_URL = LMS_ROOT_URL + '/logout'
 FRONTEND_REGISTER_URL = LMS_ROOT_URL + '/register'
 ########################### PIPELINE #################################
 
diff --git a/cms/urls.py b/cms/urls.py
index fa0fe871b0..d82cece189 100644
--- a/cms/urls.py
+++ b/cms/urls.py
@@ -44,6 +44,8 @@ COURSELIKE_KEY_PATTERN = r'(?P<course_key_string>({}|{}))'.format(
 # Pattern to match a library key only
 LIBRARY_KEY_PATTERN = r'(?P<library_key_string>library-v1:[^/+]+\+[^/+]+)'
 
+# oauth2_urlpatterns needs to be first to override any other login and
+# logout related views.
 urlpatterns = oauth2_urlpatterns + [
     url(r'', include('openedx.core.djangoapps.user_authn.urls_common')),
     url(r'', include('common.djangoapps.student.urls')),
diff --git a/docs/guides/studio_oauth.rst b/docs/guides/studio_oauth.rst
index f0d6b2a892..8f0d381e85 100644
--- a/docs/guides/studio_oauth.rst
+++ b/docs/guides/studio_oauth.rst
@@ -65,3 +65,11 @@ Config and code changes to be performed after all environments are using OAuth f
 - Remove ``LOGIN_URL`` overrides from all environments (devstack and others)
 - Remove remaining ``ARCH-1253`` detritus (login redirect)
 - Remove this doc!
+
+Declining the migration
+-----------------------
+
+Untested instructions for continuing to keep the shared sessions:
+
+- Override ``FRONTEND_LOGOUT_URL`` for Studio to be ``<LMS base>/logout``
+- Override ``LOGIN_URL`` for Studio to be ``<LMS base>/login``
diff --git a/openedx/core/djangoapps/user_authn/urls_common.py b/openedx/core/djangoapps/user_authn/urls_common.py
index 0268332907..0fce4a5e67 100644
--- a/openedx/core/djangoapps/user_authn/urls_common.py
+++ b/openedx/core/djangoapps/user_authn/urls_common.py
@@ -65,6 +65,9 @@ urlpatterns = [
     # Login Refresh of JWT Cookies
     url(r'^login_refresh$', login.login_refresh, name="login_refresh"),
 
+    # WARNING: This is similar to auth_backends ^logout/$ (which has a
+    # trailing slash); LMS uses this view, but Studio links to the
+    # auth_backends logout view.
     url(r'^logout$', logout.LogoutView.as_view(), name='logout'),
 
     # Moved from user_api/legacy_urls.py