diff --git a/channels_redis/core.py b/channels_redis/core.py
index b722d030..002c8e54 100644
--- a/channels_redis/core.py
+++ b/channels_redis/core.py
@@ -132,10 +132,11 @@ def create_pool(self, index):
         if "address" in host:
             return aioredis.ConnectionPool.from_url(host["address"])
         elif "master_name" in host:
-            host_kwargs = deepcopy(host)
-            sentinels = host_kwargs.pop("sentinels")
-            master_name = host_kwargs.pop("master_name")
-            sentinel_kwargs = host_kwargs.pop("sentinel_kwargs", None)
+            # copy host dict to prevent original one from being modified
+            host= host.copy()
+            sentinels = host.pop("sentinels")
+            master_name = host.pop("master_name")
+            sentinel_kwargs = host.pop("sentinel_kwargs", None)
             return aioredis.sentinel.SentinelConnectionPool(
                 master_name,
                 aioredis.sentinel.Sentinel(sentinels, sentinel_kwargs=sentinel_kwargs),