diff --git a/jupyterhub_traefik_proxy/redis.py b/jupyterhub_traefik_proxy/redis.py
index 738b2e13..71ea3ca7 100644
--- a/jupyterhub_traefik_proxy/redis.py
+++ b/jupyterhub_traefik_proxy/redis.py
@@ -1,6 +1,7 @@
 """Redis backend"""
 
 import asyncio
+from functools import partial
 from urllib.parse import urlparse
 
 from traitlets import Any, Dict, Unicode, default
@@ -69,7 +70,12 @@ async def _cleanup(self):
         f = super()._cleanup()
         if f is not None:
             await f
-        await self.redis.close()
+        if hasattr(self.redis, 'aclose'):
+            aclose = self.redis.aclose
+        else:
+            # redis < 5.0.1
+            aclose = self.redis.close
+        await aclose()
 
     def _setup_traefik_static_config(self):
         self.log.debug("Setting up the redis provider in the traefik static config")
@@ -115,7 +121,7 @@ def _register_delete_script(self):
         """
         _delete_lua = """
         local all_keys = {};
-        local cursor = "";
+        local cursor = "0";
         repeat
             local result = redis.call("SCAN", cursor, "match", ARGV[1], "count", ARGV[2])
             cursor = result[1];
@@ -144,11 +150,11 @@ async def _kv_atomic_delete(self, *keys):
                 prefix = key + "*"
                 self.log.debug("Deleting redis tree %s", prefix)
                 f = asyncio.ensure_future(self._delete_script(args=[prefix, 100]))
-                f.add_done_callback(
-                    lambda f: self.log.debug(
-                        "Deleted %i keys in %s", f.result(), prefix
-                    )
-                )
+
+                def _log_delete(_prefix, f):
+                    self.log.debug("Deleted %i keys in %s", f.result(), _prefix)
+
+                f.add_done_callback(partial(_log_delete, prefix))
                 futures.append(f)
             else:
                 to_delete.append(key)
diff --git a/tests/conftest.py b/tests/conftest.py
index 6c59c0d6..14c0fc75 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -418,6 +418,7 @@ async def external_redis_proxy(launch_traefik_redis, proxy_args):
     )
     await proxy._start_future
     yield proxy
+    await proxy._cleanup()
 
 
 @pytest.fixture
@@ -801,6 +802,7 @@ async def _wait_for_redis():
     from redis.asyncio import Redis
 
     async def _check_redis():
+        r = None
         try:
             r = Redis(
                 port=Config.redis_port,
@@ -811,6 +813,10 @@ async def _check_redis():
         except redis.exceptions.ConnectionError as e:
             print(e)
             return False
+        finally:
+            if r is not None:
+                await r.aclose()
+
         return True
 
     await exponential_backoff(