diff --git a/matemat/webserver/httpd.py b/matemat/webserver/httpd.py
index 3892ac8..1f99aa1 100644
--- a/matemat/webserver/httpd.py
+++ b/matemat/webserver/httpd.py
@@ -1,5 +1,5 @@
 
-from typing import Any, Callable, Dict, Tuple, Union
+from typing import Any, Callable, Dict, Tuple, Type, Union
 
 import traceback
 
@@ -89,6 +89,23 @@ def pagelet(path: str):
     return http_handler
 
 
+class MatematHTTPServer(HTTPServer):
+    """
+    A http.server.HTTPServer subclass that acts as a container for data that must be persistent between requests.
+    """
+
+    def __init__(self,
+                 server_address: Any,
+                 handler: Type[BaseHTTPRequestHandler],
+                 webroot: str,
+                 bind_and_activate: bool = True) -> None:
+        super().__init__(server_address, handler, bind_and_activate)
+        # Resolve webroot directory
+        self.webroot = os.path.abspath(webroot)
+        # Set up session vars dict
+        self.session_vars: Dict[str, Tuple[datetime, Dict[str, Any]]] = dict()
+
+
 class MatematWebserver(object):
     """
     Then main webserver class, internally uses Python's http.server.
@@ -120,11 +137,7 @@ class MatematWebserver(object):
             # Rewrite IPv4 address to IPv6-mapped form
             listen = f'::ffff:{listen}'
         # Create the http server
-        self._httpd = HTTPServer((listen, port), HttpHandler)
-        # Set up session vars dict
-        self._httpd.session_vars: Dict[str, Tuple[datetime, Dict[str, Any]]] = dict()
-        # Resolve webroot directory
-        self._httpd.webroot = os.path.abspath(webroot)
+        self._httpd = MatematHTTPServer((listen, port), HttpHandler, webroot)
 
     def start(self) -> None:
         """
@@ -143,6 +156,7 @@ class HttpHandler(BaseHTTPRequestHandler):
 
     def __init__(self, request: bytes, client_address: Tuple[str, int], server: HTTPServer) -> None:
         super().__init__(request, client_address, server)
+        self.server: MatematHTTPServer
 
     @property
     def server_version(self) -> str:
diff --git a/matemat/webserver/requestargs.py b/matemat/webserver/requestargs.py
index 2150b31..373db90 100644
--- a/matemat/webserver/requestargs.py
+++ b/matemat/webserver/requestargs.py
@@ -50,7 +50,7 @@ class RequestArguments(object):
         """
         return _View.of(self.__container[key])
 
-    def __iter__(self) -> Iterator['RequestArguments']:
+    def __iter__(self) -> Iterator['RequestArgument']:
         """
         Returns an iterator over the values in this instance.  Values are represented as immutable views.
 
diff --git a/matemat/webserver/util.py b/matemat/webserver/util.py
index 6e19d7b..c95d303 100644
--- a/matemat/webserver/util.py
+++ b/matemat/webserver/util.py
@@ -97,7 +97,7 @@ def parse_args(request: str, postbody: Optional[bytes] = None, enctype: str = 't
     tokens = urllib.parse.urlparse(request)
     # Parse the GET arguments
     if len(tokens.query) == 0:
-        getargs = dict()
+        getargs: Dict[str, List[str]] = dict()
     else:
         getargs = urllib.parse.parse_qs(tokens.query, strict_parsing=True, keep_blank_values=True, errors='strict')
 
@@ -112,7 +112,7 @@ def parse_args(request: str, postbody: Optional[bytes] = None, enctype: str = 't
             # Parse the POST body
             pb: str = postbody.decode('utf-8')
             if len(pb) == 0:
-                postargs = dict()
+                postargs: Dict[str, List[str]] = dict()
             else:
                 postargs = urllib.parse.parse_qs(pb, strict_parsing=True, keep_blank_values=True, errors='strict')
             # Write all POST values into the dict, overriding potential duplicates from GET