diff --git a/postfix_mta_sts_resolver/redis_cache.py b/postfix_mta_sts_resolver/redis_cache.py
index 8c73fb2188ffd4cee8c8c9a924a07acc9496d4d3..2a838a960f6a614b5103afe35bec7dafa251a856 100644
--- a/postfix_mta_sts_resolver/redis_cache.py
+++ b/postfix_mta_sts_resolver/redis_cache.py
@@ -36,7 +36,7 @@ class RedisCache(BaseCache):
 
     async def setup(self):
         url = self._opts['url']
-        opts = dict((k,v) for k, v in self._opts if k != 'url')
+        opts = dict((k,v) for k, v in self._opts.items() if k != 'url')
         self._pool = aioredis.from_url(url, **opts)
 
     async def get(self, key):