diff --git a/zulip/integrations/bridge_with_matrix/matrix_bridge.py b/zulip/integrations/bridge_with_matrix/matrix_bridge.py
index 9ff08d27..6a6bb00f 100755
--- a/zulip/integrations/bridge_with_matrix/matrix_bridge.py
+++ b/zulip/integrations/bridge_with_matrix/matrix_bridge.py
@@ -12,7 +12,7 @@ import urllib.request
 from collections import OrderedDict
 from concurrent.futures import ThreadPoolExecutor
 from io import BytesIO
-from typing import Any, Dict, List, Match, Optional, Set, Tuple, Type, Union
+from typing import Any, ClassVar, Dict, List, Match, Optional, Set, Tuple, Type, Union
 
 import nio
 from nio.responses import (
@@ -52,7 +52,7 @@ class MatrixToZulip:
     Matrix -> Zulip
     """
 
-    non_formatted_messages: Dict[Type[nio.Event], str] = {
+    non_formatted_messages: ClassVar[Dict[Type[nio.Event], str]] = {
         nio.StickerEvent: "sticker",
     }
 
diff --git a/zulip/integrations/bridge_with_matrix/test_matrix.py b/zulip/integrations/bridge_with_matrix/test_matrix.py
index 1689e72a..d5837eea 100644
--- a/zulip/integrations/bridge_with_matrix/test_matrix.py
+++ b/zulip/integrations/bridge_with_matrix/test_matrix.py
@@ -5,7 +5,7 @@ import sys
 from contextlib import contextmanager
 from subprocess import PIPE, Popen
 from tempfile import mkdtemp
-from typing import Any, Awaitable, Callable, Iterator, List
+from typing import Any, Awaitable, Callable, Final, Iterator, List
 from unittest import TestCase, mock
 
 import nio
@@ -209,13 +209,13 @@ class MatrixBridgeMatrixToZulipTests(TestCase):
 
 class MatrixBridgeZulipToMatrixTests(TestCase):
     room = mock.MagicMock()
-    valid_zulip_config = dict(
+    valid_zulip_config: Final = dict(
         stream="some stream",
         topic="some topic",
         email="some@email",
         bridges={("some stream", "some topic"): room},
     )
-    valid_msg = dict(
+    valid_msg: Final = dict(
         sender_email="John@Smith.smith",  # must not be equal to config:email
         sender_id=42,
         type="stream",  # Can only mirror Zulip streams
diff --git a/zulip/integrations/zephyr/zephyr_ctypes.py b/zulip/integrations/zephyr/zephyr_ctypes.py
index d1fb9b4f..2e720167 100644
--- a/zulip/integrations/zephyr/zephyr_ctypes.py
+++ b/zulip/integrations/zephyr/zephyr_ctypes.py
@@ -32,10 +32,10 @@ sa_family_t = c_ushort
 
 
 class sockaddr(Structure):
-    _fields_ = [
+    _fields_ = (
         ("sa_family", sa_family_t),
         ("sa_data", c_char * 14),
-    ]
+    )
 
 
 # --- glibc/inet/netinet/in.h ---
@@ -45,34 +45,30 @@ in_addr_t = c_uint32
 
 
 class in_addr(Structure):
-    _fields_ = [
-        ("s_addr", in_addr_t),
-    ]
+    _fields_ = (("s_addr", in_addr_t),)
 
 
 class sockaddr_in(Structure):
-    _fields_ = [
+    _fields_ = (
         ("sin_family", sa_family_t),
         ("sin_port", in_port_t),
         ("sin_addr", in_addr),
         ("sin_zero", c_uint8 * 8),
-    ]
+    )
 
 
 class in6_addr(Structure):
-    _fields_ = [
-        ("s6_addr", c_uint8 * 16),
-    ]
+    _fields_ = (("s6_addr", c_uint8 * 16),)
 
 
 class sockaddr_in6(Structure):
-    _fields_ = [
+    _fields_ = (
         ("sin6_family", sa_family_t),
         ("sin6_port", in_port_t),
         ("sin6_flowinfo", c_uint32),
         ("sin6_addr", in6_addr),
         ("sin6_scope_id", c_uint32),
-    ]
+    )
 
 
 # --- glibc/stdlib/stdlib.h ---
@@ -93,32 +89,32 @@ ZNotice_Kind_t = c_int
 
 
 class _ZTimeval(Structure):
-    _fields_ = [
+    _fields_ = (
         ("tv_sec", c_int),
         ("tv_usec", c_int),
-    ]
+    )
 
 
 class ZUnique_Id_t(Structure):
-    _fields_ = [
+    _fields_ = (
         ("zuid_addr", in_addr),
         ("tv", _ZTimeval),
-    ]
+    )
 
 
 ZChecksum_t = c_uint
 
 
 class _ZSenderSockaddr(Union):
-    _fields_ = [
+    _fields_ = (
         ("sa", sockaddr),
         ("ip4", sockaddr_in),
         ("ip6", sockaddr_in6),
-    ]
+    )
 
 
 class ZNotice_t(Structure):
-    _fields_ = [
+    _fields_ = (
         ("z_packet", c_char_p),
         ("z_version", c_char_p),
         ("z_kind", ZNotice_Kind_t),
@@ -147,15 +143,15 @@ class ZNotice_t(Structure):
         ("z_message_len", c_int),
         ("z_num_hdr_fields", c_uint),
         ("z_hdr_fields", POINTER(c_char_p)),
-    ]
+    )
 
 
 class ZSubscription_t(Structure):
-    _fields_ = [
+    _fields_ = (
         ("zsub_recipient", c_char_p),
         ("zsub_class", c_char_p),
         ("zsub_classinst", c_char_p),
-    ]
+    )
 
 
 Code_t = c_int
diff --git a/zulip/integrations/zephyr/zephyr_mirror_backend.py b/zulip/integrations/zephyr/zephyr_mirror_backend.py
index da3161fa..608c7db7 100755
--- a/zulip/integrations/zephyr/zephyr_mirror_backend.py
+++ b/zulip/integrations/zephyr/zephyr_mirror_backend.py
@@ -14,6 +14,7 @@ import tempfile
 import textwrap
 import time
 from ctypes import POINTER, byref, c_char, c_int, c_ushort
+from enum import Enum, auto
 from pathlib import Path
 from queue import Queue
 from threading import Thread
@@ -29,8 +30,10 @@ from zulip import RandomExponentialBackoff
 DEFAULT_SITE = "https://api.zulip.com"
 
 
-class States:
-    Startup, ZulipToZephyr, ZephyrToZulip = list(range(3))
+class States(Enum):
+    Startup = auto()
+    ZulipToZephyr = auto()
+    ZephyrToZulip = auto()
 
 
 CURRENT_STATE = States.Startup
diff --git a/zulip_bots/zulip_bots/bots/beeminder/test_beeminder.py b/zulip_bots/zulip_bots/bots/beeminder/test_beeminder.py
index 6d4b6a17..bcd598ab 100644
--- a/zulip_bots/zulip_bots/bots/beeminder/test_beeminder.py
+++ b/zulip_bots/zulip_bots/bots/beeminder/test_beeminder.py
@@ -1,3 +1,4 @@
+from typing import Final
 from unittest.mock import patch
 
 from requests.exceptions import ConnectionError
@@ -8,7 +9,7 @@ from zulip_bots.test_lib import BotTestCase, DefaultTests, StubBotHandler
 
 class TestBeeminderBot(BotTestCase, DefaultTests):
     bot_name = "beeminder"
-    normal_config = {"auth_token": "XXXXXX", "username": "aaron", "goalname": "goal"}
+    normal_config: Final = {"auth_token": "XXXXXX", "username": "aaron", "goalname": "goal"}
 
     help_message = """
 You can add datapoints towards your beeminder goals \
diff --git a/zulip_bots/zulip_bots/bots/connect_four/connect_four.py b/zulip_bots/zulip_bots/bots/connect_four/connect_four.py
index 96cc281b..f076e080 100644
--- a/zulip_bots/zulip_bots/bots/connect_four/connect_four.py
+++ b/zulip_bots/zulip_bots/bots/connect_four/connect_four.py
@@ -5,7 +5,7 @@ from zulip_bots.game_handler import GameAdapter
 
 
 class ConnectFourMessageHandler:
-    tokens = [":blue_circle:", ":red_circle:"]
+    tokens = (":blue_circle:", ":red_circle:")
 
     def parse_board(self, board: Any) -> str:
         # Header for the top of the board
diff --git a/zulip_bots/zulip_bots/bots/connect_four/test_connect_four.py b/zulip_bots/zulip_bots/bots/connect_four/test_connect_four.py
index d1a7ed2c..cbfde75d 100644
--- a/zulip_bots/zulip_bots/bots/connect_four/test_connect_four.py
+++ b/zulip_bots/zulip_bots/bots/connect_four/test_connect_four.py
@@ -1,4 +1,4 @@
-from typing import Dict, List
+from typing import Dict, Final, List
 
 from typing_extensions import override
 
@@ -99,7 +99,7 @@ class TestConnectFourBot(BotTestCase, DefaultTests):
 The first player to get 4 in a row wins!\n Good Luck!",
         )
 
-    blank_board = [
+    blank_board: Final = [
         [0, 0, 0, 0, 0, 0, 0],
         [0, 0, 0, 0, 0, 0, 0],
         [0, 0, 0, 0, 0, 0, 0],
@@ -108,7 +108,7 @@ The first player to get 4 in a row wins!\n Good Luck!",
         [0, 0, 0, 0, 0, 0, 0],
     ]
 
-    almost_win_board = [
+    almost_win_board: Final = [
         [0, 0, 0, 0, 0, 0, 0],
         [0, 0, 0, 0, 0, 0, 0],
         [0, 0, 0, 0, 0, 0, 0],
@@ -117,7 +117,7 @@ The first player to get 4 in a row wins!\n Good Luck!",
         [1, -1, 0, 0, 0, 0, 0],
     ]
 
-    almost_draw_board = [
+    almost_draw_board: Final = [
         [1, -1, 1, -1, 1, -1, 0],
         [0, 0, 0, 0, 0, 0, 1],
         [0, 0, 0, 0, 0, 0, -1],
diff --git a/zulip_bots/zulip_bots/bots/dropbox_share/test_dropbox_share.py b/zulip_bots/zulip_bots/bots/dropbox_share/test_dropbox_share.py
index d1fead3b..5fa4f8c8 100644
--- a/zulip_bots/zulip_bots/bots/dropbox_share/test_dropbox_share.py
+++ b/zulip_bots/zulip_bots/bots/dropbox_share/test_dropbox_share.py
@@ -1,3 +1,4 @@
+from typing import Final
 from unittest.mock import patch
 
 from zulip_bots.bots.dropbox_share.test_util import (
@@ -75,7 +76,7 @@ def get_help() -> str:
 
 class TestDropboxBot(BotTestCase, DefaultTests):
     bot_name = "dropbox_share"
-    config_info = {"access_token": "1234567890"}
+    config_info: Final = {"access_token": "1234567890"}
 
     def test_bot_responds_to_empty_message(self):
         with self.mock_config_info(self.config_info):
diff --git a/zulip_bots/zulip_bots/bots/flock/test_flock.py b/zulip_bots/zulip_bots/bots/flock/test_flock.py
index 9efb1c88..92058907 100644
--- a/zulip_bots/zulip_bots/bots/flock/test_flock.py
+++ b/zulip_bots/zulip_bots/bots/flock/test_flock.py
@@ -1,3 +1,4 @@
+from typing import Final
 from unittest.mock import patch
 
 from requests.exceptions import ConnectionError
@@ -7,9 +8,9 @@ from zulip_bots.test_lib import BotTestCase, DefaultTests
 
 class TestFlockBot(BotTestCase, DefaultTests):
     bot_name = "flock"
-    normal_config = {"token": "12345"}
+    normal_config: Final = {"token": "12345"}
 
-    message_config = {"token": "12345", "text": "Ricky: test message", "to": "u:somekey"}
+    message_config: Final = {"token": "12345", "text": "Ricky: test message", "to": "u:somekey"}
 
     help_message = """
 You can send messages to any Flock user associated with your account from Zulip.
diff --git a/zulip_bots/zulip_bots/bots/front/front.py b/zulip_bots/zulip_bots/bots/front/front.py
index 2f89c91f..297f59e4 100644
--- a/zulip_bots/zulip_bots/bots/front/front.py
+++ b/zulip_bots/zulip_bots/bots/front/front.py
@@ -8,13 +8,13 @@ from zulip_bots.lib import BotHandler
 
 class FrontHandler:
     FRONT_API = "https://api2.frontapp.com/conversations/{}"
-    COMMANDS = [
+    COMMANDS = (
         ("archive", "Archive a conversation."),
         ("delete", "Delete a conversation."),
         ("spam", "Mark a conversation as spam."),
         ("open", "Restore a conversation."),
         ("comment <text>", "Leave a comment."),
-    ]
+    )
     CNV_ID_REGEXP = "cnv_(?P<id>[0-9a-z]+)"
     COMMENT_PREFIX = "comment "
 
diff --git a/zulip_bots/zulip_bots/bots/game_handler_bot/game_handler_bot.py b/zulip_bots/zulip_bots/bots/game_handler_bot/game_handler_bot.py
index d9c6538e..d1d6eb9a 100644
--- a/zulip_bots/zulip_bots/bots/game_handler_bot/game_handler_bot.py
+++ b/zulip_bots/zulip_bots/bots/game_handler_bot/game_handler_bot.py
@@ -4,7 +4,7 @@ from zulip_bots.game_handler import BadMoveError, GameAdapter
 
 
 class GameHandlerBotMessageHandler:
-    tokens = [":blue_circle:", ":red_circle:"]
+    tokens = (":blue_circle:", ":red_circle:")
 
     def parse_board(self, board: Any) -> str:
         return "foo"
diff --git a/zulip_bots/zulip_bots/bots/game_of_fifteen/game_of_fifteen.py b/zulip_bots/zulip_bots/bots/game_of_fifteen/game_of_fifteen.py
index 864217e3..4a4ae50a 100644
--- a/zulip_bots/zulip_bots/bots/game_of_fifteen/game_of_fifteen.py
+++ b/zulip_bots/zulip_bots/bots/game_of_fifteen/game_of_fifteen.py
@@ -1,13 +1,13 @@
 import copy
-from typing import Any, Dict, List, Tuple
+from typing import Any, Dict, Final, List, Tuple
 
 from zulip_bots.game_handler import BadMoveError, GameAdapter
 
 
 class GameOfFifteenModel:
-    final_board = [[0, 1, 2], [3, 4, 5], [6, 7, 8]]
+    final_board: Final = [[0, 1, 2], [3, 4, 5], [6, 7, 8]]
 
-    initial_board = [[8, 7, 6], [5, 4, 3], [2, 1, 0]]
+    initial_board: Final = [[8, 7, 6], [5, 4, 3], [2, 1, 0]]
 
     def __init__(self, board: Any = None) -> None:
         if board is not None:
@@ -81,7 +81,7 @@ class GameOfFifteenModel:
 
 
 class GameOfFifteenMessageHandler:
-    tiles = {
+    tiles: Final = {
         "0": ":grey_question:",
         "1": ":one:",
         "2": ":two:",
diff --git a/zulip_bots/zulip_bots/bots/game_of_fifteen/test_game_of_fifteen.py b/zulip_bots/zulip_bots/bots/game_of_fifteen/test_game_of_fifteen.py
index c4ac3c6b..fc03db79 100644
--- a/zulip_bots/zulip_bots/bots/game_of_fifteen/test_game_of_fifteen.py
+++ b/zulip_bots/zulip_bots/bots/game_of_fifteen/test_game_of_fifteen.py
@@ -1,4 +1,4 @@
-from typing import Dict, List, Tuple
+from typing import Dict, Final, List, Tuple
 
 from zulip_bots.bots.game_of_fifteen.game_of_fifteen import GameOfFifteenModel
 from zulip_bots.game_handler import BadMoveError
@@ -68,7 +68,7 @@ class TestGameOfFifteenBot(BotTestCase, DefaultTests):
             "To make a move, type @-mention `move <tile1> <tile2> ...`",
         )
 
-    winning_board = [[0, 1, 2], [3, 4, 5], [6, 7, 8]]
+    winning_board: Final = [[0, 1, 2], [3, 4, 5], [6, 7, 8]]
 
     def test_game_of_fifteen_logic(self) -> None:
         def confirm_available_moves(
diff --git a/zulip_bots/zulip_bots/bots/github_detail/test_github_detail.py b/zulip_bots/zulip_bots/bots/github_detail/test_github_detail.py
index 87778102..ba6a86cf 100644
--- a/zulip_bots/zulip_bots/bots/github_detail/test_github_detail.py
+++ b/zulip_bots/zulip_bots/bots/github_detail/test_github_detail.py
@@ -1,3 +1,5 @@
+from typing import Final
+
 from typing_extensions import override
 
 from zulip_bots.test_file_utils import get_bot_message_handler
@@ -6,8 +8,8 @@ from zulip_bots.test_lib import BotTestCase, DefaultTests, StubBotHandler
 
 class TestGithubDetailBot(BotTestCase, DefaultTests):
     bot_name = "github_detail"
-    mock_config = {"owner": "zulip", "repo": "zulip"}
-    empty_config = {"owner": "", "repo": ""}
+    mock_config: Final = {"owner": "zulip", "repo": "zulip"}
+    empty_config: Final = {"owner": "", "repo": ""}
 
     # Overrides default test_bot_usage().
     @override
diff --git a/zulip_bots/zulip_bots/bots/incrementor/incrementor.py b/zulip_bots/zulip_bots/bots/incrementor/incrementor.py
index ea42a08b..1c008002 100644
--- a/zulip_bots/zulip_bots/bots/incrementor/incrementor.py
+++ b/zulip_bots/zulip_bots/bots/incrementor/incrementor.py
@@ -1,12 +1,12 @@
 # See readme.md for instructions on running this code.
 
-from typing import Dict
+from typing import Dict, Final
 
 from zulip_bots.lib import BotHandler, use_storage
 
 
 class IncrementorHandler:
-    META = {
+    META: Final = {
         "name": "Incrementor",
         "description": "Example bot to test the update_message() function.",
     }
diff --git a/zulip_bots/zulip_bots/bots/jira/test_jira.py b/zulip_bots/zulip_bots/bots/jira/test_jira.py
index 1c7c0928..4f0f947c 100644
--- a/zulip_bots/zulip_bots/bots/jira/test_jira.py
+++ b/zulip_bots/zulip_bots/bots/jira/test_jira.py
@@ -1,22 +1,24 @@
+from typing import Final
+
 from zulip_bots.test_lib import BotTestCase, DefaultTests
 
 
 class TestJiraBot(BotTestCase, DefaultTests):
     bot_name = "jira"
 
-    MOCK_CONFIG_INFO = {
+    MOCK_CONFIG_INFO: Final = {
         "username": "example@example.com",
         "password": "qwerty!123",
         "domain": "example.atlassian.net",
     }
 
-    MOCK_SCHEME_CONFIG_INFO = {
+    MOCK_SCHEME_CONFIG_INFO: Final = {
         "username": "example@example.com",
         "password": "qwerty!123",
         "domain": "http://example.atlassian.net",
     }
 
-    MOCK_DISPLAY_CONFIG_INFO = {
+    MOCK_DISPLAY_CONFIG_INFO: Final = {
         "username": "example@example.com",
         "password": "qwerty!123",
         "domain": "example.atlassian.net",
diff --git a/zulip_bots/zulip_bots/bots/merels/merels.py b/zulip_bots/zulip_bots/bots/merels/merels.py
index ca9860e6..e49d336f 100644
--- a/zulip_bots/zulip_bots/bots/merels/merels.py
+++ b/zulip_bots/zulip_bots/bots/merels/merels.py
@@ -1,4 +1,4 @@
-from typing import Any, List
+from typing import Any, Final, List
 
 from zulip_bots.game_handler import GameAdapter, SamePlayerMoveError
 
@@ -52,7 +52,7 @@ class MerelsModel:
 
 
 class MerelsMessageHandler:
-    tokens = [":o_button:", ":cross_mark_button:"]
+    tokens = (":o_button:", ":cross_mark_button:")
 
     def parse_board(self, board: Any) -> str:
         return board
@@ -73,7 +73,7 @@ class MerelsHandler(GameAdapter):
     "@mention-bot".
     """
 
-    META = {
+    META: Final = {
         "name": "merels",
         "description": "Lets you play merels against any player.",
     }
diff --git a/zulip_bots/zulip_bots/bots/stack_overflow/stack_overflow.py b/zulip_bots/zulip_bots/bots/stack_overflow/stack_overflow.py
index 5bad1fcd..4fa8e66a 100644
--- a/zulip_bots/zulip_bots/bots/stack_overflow/stack_overflow.py
+++ b/zulip_bots/zulip_bots/bots/stack_overflow/stack_overflow.py
@@ -1,5 +1,5 @@
 import logging
-from typing import Dict, Optional
+from typing import Dict, Final, Optional
 
 import requests
 
@@ -18,7 +18,7 @@ class StackOverflowHandler:
     the same stream that it was called from.
     """
 
-    META = {
+    META: Final = {
         "name": "StackOverflow",
         "description": "Searches Stack Overflow for a query and returns the top 3 articles.",
     }
diff --git a/zulip_bots/zulip_bots/bots/tictactoe/tictactoe.py b/zulip_bots/zulip_bots/bots/tictactoe/tictactoe.py
index 47f5f6f7..4aa1fd9f 100644
--- a/zulip_bots/zulip_bots/bots/tictactoe/tictactoe.py
+++ b/zulip_bots/zulip_bots/bots/tictactoe/tictactoe.py
@@ -1,6 +1,6 @@
 import copy
 import random
-from typing import Any, List, Tuple
+from typing import Any, Final, List, Tuple
 
 from typing_extensions import override
 
@@ -15,7 +15,7 @@ class TicTacToeModel:
     smarter = True
     # If smarter is True, the computer will do some extra thinking - it'll be harder for the user.
 
-    triplets = [
+    triplets: Final = [
         [(0, 0), (0, 1), (0, 2)],  # Row 1
         [(1, 0), (1, 1), (1, 2)],  # Row 2
         [(2, 0), (2, 1), (2, 2)],  # Row 3
@@ -26,7 +26,7 @@ class TicTacToeModel:
         [(0, 2), (1, 1), (2, 0)],  # Diagonal 2
     ]
 
-    initial_board = [[0, 0, 0], [0, 0, 0], [0, 0, 0]]
+    initial_board: Final = [[0, 0, 0], [0, 0, 0], [0, 0, 0]]
 
     def __init__(self, board: Any = None) -> None:
         if board is not None:
@@ -203,7 +203,7 @@ class TicTacToeModel:
 
 
 class TicTacToeMessageHandler:
-    tokens = [":x:", ":o:"]
+    tokens = (":x:", ":o:")
 
     def parse_row(self, row: Tuple[int, int], row_num: int) -> str:
         """Takes the row passed in as a list and returns it as a string."""
@@ -248,7 +248,7 @@ class TicTacToeHandler(GameAdapter):
     "@mention-bot".
     """
 
-    META = {
+    META: Final = {
         "name": "TicTacToe",
         "description": "Lets you play Tic-tac-toe against a computer.",
     }
diff --git a/zulip_bots/zulip_bots/bots/twitpost/test_twitpost.py b/zulip_bots/zulip_bots/bots/twitpost/test_twitpost.py
index c62c4079..5161e172 100644
--- a/zulip_bots/zulip_bots/bots/twitpost/test_twitpost.py
+++ b/zulip_bots/zulip_bots/bots/twitpost/test_twitpost.py
@@ -1,3 +1,4 @@
+from typing import Final
 from unittest.mock import patch
 
 from zulip_bots.test_file_utils import get_bot_message_handler, read_bot_fixture_data
@@ -6,7 +7,7 @@ from zulip_bots.test_lib import BotTestCase, DefaultTests, StubBotHandler
 
 class TestTwitpostBot(BotTestCase, DefaultTests):
     bot_name = "twitpost"
-    mock_config = {
+    mock_config: Final = {
         "consumer_key": "abcdefghijklmnopqrstuvwxy",
         "consumer_secret": "aabbccddeeffgghhiijjkkllmmnnooppqqrrssttuuvvwwxxyy",
         "access_token": "123456789012345678-ABCDefgh1234afdsa678lKj6gHhslsi",
diff --git a/zulip_bots/zulip_bots/bots/virtual_fs/virtual_fs.py b/zulip_bots/zulip_bots/bots/virtual_fs/virtual_fs.py
index 694bc538..001f7e7f 100644
--- a/zulip_bots/zulip_bots/bots/virtual_fs/virtual_fs.py
+++ b/zulip_bots/zulip_bots/bots/virtual_fs/virtual_fs.py
@@ -2,13 +2,13 @@
 
 import os
 import re
-from typing import Any, Dict, List, Set, Tuple, Union
+from typing import Any, Dict, Final, List, Set, Tuple, Union
 
 from zulip_bots.lib import BotHandler
 
 
 class VirtualFsHandler:
-    META = {
+    META: Final = {
         "name": "VirtualFs",
         "description": "Provides a simple, permanent file system to store and retrieve strings.",
     }
diff --git a/zulip_bots/zulip_bots/bots/wikipedia/wikipedia.py b/zulip_bots/zulip_bots/bots/wikipedia/wikipedia.py
index ff707fbf..385af7a6 100644
--- a/zulip_bots/zulip_bots/bots/wikipedia/wikipedia.py
+++ b/zulip_bots/zulip_bots/bots/wikipedia/wikipedia.py
@@ -1,5 +1,5 @@
 import logging
-from typing import Dict
+from typing import Dict, Final
 
 import requests
 
@@ -20,7 +20,7 @@ class WikipediaHandler:
     kind of external issue tracker as well.
     """
 
-    META = {
+    META: Final = {
         "name": "Wikipedia",
         "description": "Searches Wikipedia for a term and returns the top 3 articles.",
     }
diff --git a/zulip_bots/zulip_bots/bots/witai/test_witai.py b/zulip_bots/zulip_bots/bots/witai/test_witai.py
index a5c7a60e..cafc6eb4 100644
--- a/zulip_bots/zulip_bots/bots/witai/test_witai.py
+++ b/zulip_bots/zulip_bots/bots/witai/test_witai.py
@@ -1,4 +1,4 @@
-from typing import Any, Dict, Optional
+from typing import Any, Dict, Final, Optional
 from unittest.mock import patch
 
 from typing_extensions import override
@@ -10,13 +10,13 @@ from zulip_bots.test_lib import BotTestCase, DefaultTests, StubBotHandler
 class TestWitaiBot(BotTestCase, DefaultTests):
     bot_name = "witai"
 
-    MOCK_CONFIG_INFO = {
+    MOCK_CONFIG_INFO: Final = {
         "token": "12345678",
         "handler_location": "/Users/abcd/efgh",
         "help_message": "Qwertyuiop!",
     }
 
-    MOCK_WITAI_RESPONSE = {
+    MOCK_WITAI_RESPONSE: Final = {
         "_text": "What is your favorite food?",
         "entities": {"intent": [{"confidence": 1.0, "value": "favorite_food"}]},
     }
diff --git a/zulip_bots/zulip_bots/bots/xkcd/xkcd.py b/zulip_bots/zulip_bots/bots/xkcd/xkcd.py
index 015f27a1..691bd664 100644
--- a/zulip_bots/zulip_bots/bots/xkcd/xkcd.py
+++ b/zulip_bots/zulip_bots/bots/xkcd/xkcd.py
@@ -1,6 +1,6 @@
 import logging
 import random
-from typing import Dict, Optional
+from typing import Dict, Final, Optional
 
 import requests
 
@@ -18,7 +18,7 @@ class XkcdHandler:
     commands.
     """
 
-    META = {
+    META: Final = {
         "name": "XKCD",
         "description": "Fetches comic strips from https://xkcd.com.",
     }
diff --git a/zulip_bots/zulip_bots/bots/youtube/test_youtube.py b/zulip_bots/zulip_bots/bots/youtube/test_youtube.py
index 22922a8f..44a26812 100644
--- a/zulip_bots/zulip_bots/bots/youtube/test_youtube.py
+++ b/zulip_bots/zulip_bots/bots/youtube/test_youtube.py
@@ -1,4 +1,4 @@
-from typing import Dict
+from typing import Dict, Final
 from unittest.mock import patch
 
 from requests.exceptions import ConnectionError, HTTPError
@@ -10,7 +10,7 @@ from zulip_bots.test_lib import BotTestCase, DefaultTests, StubBotHandler
 
 class TestYoutubeBot(BotTestCase, DefaultTests):
     bot_name = "youtube"
-    normal_config: Dict[str, str] = {
+    normal_config: Final[Dict[str, str]] = {
         "key": "12345678",
         "number_of_results": "5",
         "video_region": "US",