diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6941439..8458787 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,11 @@
 
 ## 0.1
 
+### 0.1.6
+
+- Fix redis cache.
+- Encode key builder.
+
 ### 0.1.5
 
 - Fix setting expire for redis (#24)
diff --git a/examples/main.py b/examples/main.py
index 3f53a02..2ed79af 100644
--- a/examples/main.py
+++ b/examples/main.py
@@ -1,3 +1,4 @@
+import aioredis
 import uvicorn
 from fastapi import FastAPI
 from starlette.requests import Request
@@ -5,6 +6,7 @@ from starlette.responses import Response
 
 from fastapi_cache import FastAPICache
 from fastapi_cache.backends.inmemory import InMemoryBackend
+from fastapi_cache.backends.redis import RedisBackend
 from fastapi_cache.decorator import cache
 
 app = FastAPI()
@@ -20,7 +22,7 @@ async def get_ret():
 
 
 @app.get("/")
-@cache(namespace="test", expire=2)
+@cache(namespace="test", expire=20)
 async def index(request: Request, response: Response):
     return dict(ret=await get_ret())
 
@@ -32,7 +34,8 @@ async def clear():
 
 @app.on_event("startup")
 async def startup():
-    FastAPICache.init(InMemoryBackend(), prefix="fastapi-cache")
+    redis = aioredis.from_url(url="redis://localhost")
+    FastAPICache.init(RedisBackend(redis), prefix="fastapi-cache")
 
 
 if __name__ == "__main__":
diff --git a/fastapi_cache/backends/redis.py b/fastapi_cache/backends/redis.py
index c82cdd9..00e0972 100644
--- a/fastapi_cache/backends/redis.py
+++ b/fastapi_cache/backends/redis.py
@@ -10,10 +10,8 @@ class RedisBackend(Backend):
         self.redis = redis
 
     async def get_with_ttl(self, key: str) -> Tuple[int, str]:
-        p = self.redis.pipeline()
-        p.ttl(key)
-        p.get(key)
-        return await p.execute()
+        async with self.redis.pipeline(transaction=True) as pipe:
+            return await (pipe.ttl(key).get(key).execute())
 
     async def get(self, key) -> str:
         return await self.redis.get(key)
@@ -24,6 +22,6 @@ class RedisBackend(Backend):
     async def clear(self, namespace: str = None, key: str = None) -> int:
         if namespace:
             lua = f"for i, name in ipairs(redis.call('KEYS', '{namespace}:*')) do redis.call('DEL', name); end"
-            return await self.redis.eval(lua)
+            return await self.redis.eval(lua, numkeys=0)
         elif key:
             return await self.redis.delete(key)
diff --git a/fastapi_cache/coder.py b/fastapi_cache/coder.py
index dca412d..e44a6dd 100644
--- a/fastapi_cache/coder.py
+++ b/fastapi_cache/coder.py
@@ -3,9 +3,9 @@ import json
 import pickle  # nosec:B403
 from decimal import Decimal
 from typing import Any
-from fastapi.encoders import jsonable_encoder
 
 import dateutil.parser
+from fastapi.encoders import jsonable_encoder
 
 CONVERTERS = {
     "date": dateutil.parser.parse,
diff --git a/fastapi_cache/key_builder.py b/fastapi_cache/key_builder.py
index 1d63fd4..112f2dc 100644
--- a/fastapi_cache/key_builder.py
+++ b/fastapi_cache/key_builder.py
@@ -19,7 +19,7 @@ def default_key_builder(
     cache_key = (
         prefix
         + hashlib.md5(  # nosec:B303
-            f"{func.__module__}:{func.__name__}:{args}:{kwargs}"
+            f"{func.__module__}:{func.__name__}:{args}:{kwargs}".encode()
         ).hexdigest()
     )
     return cache_key
diff --git a/pyproject.toml b/pyproject.toml
index 02d42fc..fdb3005 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "fastapi-cache2"
-version = "0.1.5"
+version = "0.1.6"
 description = "Cache for FastAPI"
 authors = ["long2ice <long2ice@gmail.com>"]
 license = "Apache-2.0"