diff --git a/tests/test_fsm/storage/test_isolation.py b/tests/test_fsm/storage/test_isolation.py
index f41a2b2c..8be303c4 100644
--- a/tests/test_fsm/storage/test_isolation.py
+++ b/tests/test_fsm/storage/test_isolation.py
@@ -1,6 +1,10 @@
+from unittest import mock
+from unittest.mock import AsyncMock, patch
+
 import pytest
 
 from aiogram.fsm.storage.base import BaseEventIsolation, StorageKey
+from aiogram.fsm.storage.redis import RedisEventIsolation
 from tests.mocked_bot import MockedBot
 
 
@@ -25,3 +29,35 @@ class TestIsolations:
     ):
         async with isolation.lock(key=storage_key):
             assert True, "Are you kidding me?"
+
+
+class TestRedisEventIsolation:
+    def test_init_without_key_builder(self):
+        redis = AsyncMock()
+        isolation = RedisEventIsolation(redis=redis)
+        assert isolation.redis is redis
+
+        assert isolation.key_builder is not None
+
+    def test_init_with_key_builder(self):
+        redis = AsyncMock()
+        key_builder = AsyncMock()
+        isolation = RedisEventIsolation(redis=redis, key_builder=key_builder)
+        assert isolation.redis is redis
+        assert isolation.key_builder is key_builder
+
+    def test_create_from_url(self):
+        with patch("redis.asyncio.connection.ConnectionPool.from_url") as pool:
+            isolation = RedisEventIsolation.from_url("redis://localhost:6379/0")
+            assert isinstance(isolation, RedisEventIsolation)
+            assert isolation.redis is not None
+            assert isolation.key_builder is not None
+
+            assert pool.called_once_with("redis://localhost:6379/0")
+
+    async def test_close(self):
+        isolation = RedisEventIsolation(redis=AsyncMock())
+        await isolation.close()
+
+        # close is not called because connection should be closed from the storage
+        # assert isolation.redis.close.called_once()