diff --git a/jupyterhub/services/auth.py b/jupyterhub/services/auth.py
index 4ce9ed84..1020ae31 100644
--- a/jupyterhub/services/auth.py
+++ b/jupyterhub/services/auth.py
@@ -99,6 +99,11 @@ class _ExpiringDict(dict):
         except KeyError:
             return default
 
+    def clear(self):
+        """Clear the cache"""
+        self.values.clear()
+        self.timestamps.clear()
+
 
 class HubAuth(SingletonConfigurable):
     """A class for authenticating with JupyterHub
diff --git a/jupyterhub/tests/test_services_auth.py b/jupyterhub/tests/test_services_auth.py
index ce253e05..64326fa2 100644
--- a/jupyterhub/tests/test_services_auth.py
+++ b/jupyterhub/tests/test_services_auth.py
@@ -170,6 +170,10 @@ def test_hub_authenticated(request):
         assert r.status_code == 302
         assert auth.login_url in r.headers['Location']
 
+        # clear the cache because we are going to request
+        # the same url again with a different result
+        auth.cache.clear()
+
         # upstream 403
         m.get(bad_url, status_code=403)
         r = requests.get('http://127.0.0.1:%i' % port,