diff --git a/aiorest/handler.py b/aiorest/handler.py
index c5f4c55..23a88c9 100644
--- a/aiorest/handler.py
+++ b/aiorest/handler.py
@@ -77,7 +77,7 @@ def handle_request(self, message, payload):
             else:
                 resp_impl.add_header('Content-Length', str(len(bbody)))
 
-            headers = request.response.headers.items(getall=True)
+            headers = request.response.headers.items()
             for key, val in headers:
                 resp_impl.add_header(key, val)
 
diff --git a/aiorest/request.py b/aiorest/request.py
index 917c8a8..f01a406 100644
--- a/aiorest/request.py
+++ b/aiorest/request.py
@@ -4,7 +4,7 @@
 
 from urllib.parse import urlsplit, parse_qsl
 
-from aiohttp.multidict import MultiDict, MutableMultiDict
+from aiohttp.multidict import MultiDict, CIMultiDict, MultiDictProxy
 
 from .errors import JsonLoadError, JsonDecodeError
 
@@ -18,7 +18,7 @@
 class Response:
 
     def __init__(self):
-        self.headers = MutableMultiDict()
+        self.headers = CIMultiDict()
         self._status_code = 200
         self._cookies = http.cookies.SimpleCookie()
         self._deleted_cookies = set()
@@ -99,7 +99,7 @@ def __init__(self, host, message, req_body, *,
         self.path_url = self.host_url + self.path
         self.url = self.host_url + self.path_qs
         self.query_string = res.query
-        self.args = MultiDict(parse_qsl(res.query))
+        self.args = MultiDictProxy(MultiDict(parse_qsl(res.query)))
         self.headers = message.headers
         self.matchdict = {}
         self._request_body = req_body
@@ -159,8 +159,9 @@ def cookies(self):
         if self._cookies is None:
             raw = self.headers.get('COOKIE', '')
             parsed = http.cookies.SimpleCookie(raw)
-            self._cookies = MultiDict({key: val.value
-                                       for key, val in parsed.items()})
+            self._cookies = MultiDictProxy(MultiDict({key: val.value
+                                                      for key, val in
+                                                      parsed.items()}))
         return self._cookies
 
     def add_response_callback(self, callback, *args, **kwargs):
diff --git a/tests/cookies_test.py b/tests/cookies_test.py
index 0f41f61..fd3a81b 100644
--- a/tests/cookies_test.py
+++ b/tests/cookies_test.py
@@ -5,7 +5,7 @@
 from unittest import mock
 
 from aiorest import Request, Response
-from aiohttp.multidict import MutableMultiDict, CaseInsensitiveMultiDict
+from aiohttp import MultiDict, CIMultiDict
 
 
 class CookiesTests(unittest.TestCase):
@@ -13,11 +13,11 @@ class CookiesTests(unittest.TestCase):
     def setUp(self):
         self.loop = mock.Mock()
         self._REQUEST = aiohttp.RawRequestMessage(
-            'GET', '/some/path', '1.1', MutableMultiDict(), True, None)
+            'GET', '/some/path', '1.1', MultiDict(), True, None)
 
     def test_no_request_cookies(self):
         req = Request('host', aiohttp.RawRequestMessage(
-            'GET', '/some/path', '1.1', CaseInsensitiveMultiDict(),
+            'GET', '/some/path', '1.1', CIMultiDict(),
             True, None),
             None, loop=self.loop)