diff --git a/aiohttp/client_reqrep.py b/aiohttp/client_reqrep.py
index b75988ab1aa..c26a57355eb 100644
--- a/aiohttp/client_reqrep.py
+++ b/aiohttp/client_reqrep.py
@@ -39,14 +39,14 @@
 __all__ = ('ClientRequest', 'ClientResponse', 'RequestInfo', 'Fingerprint')
 
 
-@attr.s(frozen=True)
+@attr.s(frozen=True, slots=True)
 class ContentDisposition:
     type = attr.ib(type=str)
     parameters = attr.ib(type=MappingProxyType)
     filename = attr.ib(type=str)
 
 
-@attr.s(frozen=True)
+@attr.s(frozen=True, slots=True)
 class RequestInfo:
     url = attr.ib(type=URL)
     method = attr.ib(type=str)
diff --git a/aiohttp/helpers.py b/aiohttp/helpers.py
index 839452b491a..4ab93ff2800 100644
--- a/aiohttp/helpers.py
+++ b/aiohttp/helpers.py
@@ -143,7 +143,7 @@ def netrc_from_env():
     return netrc_obj
 
 
-@attr.s(frozen=True)
+@attr.s(frozen=True, slots=True)
 class ProxyInfo:
     proxy = attr.ib(type=str)
     proxy_auth = attr.ib(type=BasicAuth)
@@ -192,7 +192,7 @@ def isasyncgenfunction(obj):
     return False
 
 
-@attr.s(frozen=True)
+@attr.s(frozen=True, slots=True)
 class MimeType:
     type = attr.ib(type=str)
     subtype = attr.ib(type=str)
diff --git a/aiohttp/web_request.py b/aiohttp/web_request.py
index 9eee747bdcf..91f5832ad9b 100644
--- a/aiohttp/web_request.py
+++ b/aiohttp/web_request.py
@@ -27,7 +27,7 @@
 __all__ = ('BaseRequest', 'FileField', 'Request')
 
 
-@attr.s(frozen=True)
+@attr.s(frozen=True, slots=True)
 class FileField:
     name = attr.ib(type=str)
     filename = attr.ib(type=str)
diff --git a/aiohttp/web_urldispatcher.py b/aiohttp/web_urldispatcher.py
index 784dbb81d0b..4f8def2e7f1 100644
--- a/aiohttp/web_urldispatcher.py
+++ b/aiohttp/web_urldispatcher.py
@@ -37,7 +37,7 @@
 PATH_SEP = re.escape('/')
 
 
-@attr.s(frozen=True, repr=False)
+@attr.s(frozen=True, repr=False, slots=True)
 class RouteDef:
     method = attr.ib(type=str)
     path = attr.ib(type=str)
diff --git a/aiohttp/web_ws.py b/aiohttp/web_ws.py
index e31ab2e2ba0..66dc88f7098 100644
--- a/aiohttp/web_ws.py
+++ b/aiohttp/web_ws.py
@@ -28,7 +28,7 @@
 MsgType = WSMsgType
 
 
-@attr.s(frozen=True)
+@attr.s(frozen=True, slots=True)
 class WebSocketReady:
     ok = attr.ib(type=bool)
     protocol = attr.ib(type=str)