diff --git a/zulip_bots/zulip_bots/bots/baremetrics/baremetrics.py b/zulip_bots/zulip_bots/bots/baremetrics/baremetrics.py
index 5d29add..c60d237 100644
--- a/zulip_bots/zulip_bots/bots/baremetrics/baremetrics.py
+++ b/zulip_bots/zulip_bots/bots/baremetrics/baremetrics.py
@@ -23,7 +23,7 @@ class BaremetricsHandler(object):
 
         self.check_api_key(bot_handler)
 
-    def check_api_key(self, bot_handler) -> None:
+    def check_api_key(self, bot_handler: Any) -> None:
         url = "https://api.baremetrics.com/v1/account"
         test_query_response = requests.get(url, headers=self.auth_header)
         test_query_data = test_query_response.json()
diff --git a/zulip_bots/zulip_bots/bots/link_shortener/link_shortener.py b/zulip_bots/zulip_bots/bots/link_shortener/link_shortener.py
index a0e13dd..0de1289 100644
--- a/zulip_bots/zulip_bots/bots/link_shortener/link_shortener.py
+++ b/zulip_bots/zulip_bots/bots/link_shortener/link_shortener.py
@@ -19,7 +19,7 @@ class LinkShortenerHandler(object):
         self.config_info = bot_handler.get_config_info('link_shortener')
         self.check_api_key(bot_handler)
 
-    def check_api_key(self, bot_handler) -> None:
+    def check_api_key(self, bot_handler: Any) -> None:
         test_request = requests.post(
             'https://www.googleapis.com/urlshortener/v1/url',
             json={'longUrl': 'www.youtube.com/watch'},
diff --git a/zulip_bots/zulip_bots/bots/mention/mention.py b/zulip_bots/zulip_bots/bots/mention/mention.py
index 3039d82..a21d986 100644
--- a/zulip_bots/zulip_bots/bots/mention/mention.py
+++ b/zulip_bots/zulip_bots/bots/mention/mention.py
@@ -12,7 +12,7 @@ class MentionHandler(object):
 
         self.check_access_token(bot_handler)
 
-    def check_access_token(self, bot_handler) -> None:
+    def check_access_token(self, bot_handler: Any) -> None:
         test_query_header = {
             'Authorization': 'Bearer ' + self.access_token,
             'Accept-Version': '1.15',