diff --git a/responder/models.py b/responder/models.py
index 2ec0690..9450096 100644
--- a/responder/models.py
+++ b/responder/models.py
@@ -18,7 +18,6 @@ from .status_codes import HTTP_200
 
 class QueryDict(dict):
     def __init__(self, query_string):
-        query_string = query_string
         self.update(parse_qs(query_string))
 
     def __getitem__(self, key):
@@ -87,6 +86,17 @@ class QueryDict(dict):
 
 # TODO: add slots
 class Request:
+    __slots__ = [
+        "_starlette",
+        "formats",
+        "headers",
+        "mimetype",
+        "method",
+        "full_url",
+        "url",
+        "params",
+    ]
+
     def __init__(self, scope, receive):
         self._starlette = StarletteRequest(scope, receive)
         self.formats = None
@@ -152,6 +162,17 @@ class Request:
 
 
 class Response:
+    __slots__ = [
+        "req",
+        "status_code",
+        "text",
+        "content",
+        "encoding",
+        "media",
+        "headers",
+        "formats",
+    ]
+
     def __init__(self, req, *, formats):
         self.req = req
         self.status_code = HTTP_200  #: The HTTP Status Code to use for the Response.