diff --git a/zulip_bots/zulip_bots/bots/giphy/giphy.py b/zulip_bots/zulip_bots/bots/giphy/giphy.py
index d0e0c73e..f5eb3599 100644
--- a/zulip_bots/zulip_bots/bots/giphy/giphy.py
+++ b/zulip_bots/zulip_bots/bots/giphy/giphy.py
@@ -77,7 +77,7 @@ def get_url_gif_giphy(keyword: str, api_key: str) -> Union[int, str]:
     try:
         gif_url = data.json()["data"]["images"]["original"]["url"]
     except (TypeError, KeyError):  # Usually triggered by no result in Giphy.
-        raise GiphyNoResultException()
+        raise GiphyNoResultException
     return gif_url
 
 
diff --git a/zulip_bots/zulip_bots/bots/idonethis/idonethis.py b/zulip_bots/zulip_bots/bots/idonethis/idonethis.py
index 443841a6..7163c637 100644
--- a/zulip_bots/zulip_bots/bots/idonethis/idonethis.py
+++ b/zulip_bots/zulip_bots/bots/idonethis/idonethis.py
@@ -49,10 +49,10 @@ def make_API_request(
         and r.json()["error"] == "Invalid API Authentication"
     ):
         logging.error("Error authenticating, please check key " + str(r.url))
-        raise AuthenticationException()
+        raise AuthenticationException
     else:
         logging.error("Error make API request, code " + str(r.status_code) + ". json: " + r.json())
-        raise UnspecifiedProblemException()
+        raise UnspecifiedProblemException
 
 
 def api_noop() -> None:
diff --git a/zulip_bots/zulip_bots/bots/incident/incident.py b/zulip_bots/zulip_bots/bots/incident/incident.py
index 6ff1ab05..66dca582 100644
--- a/zulip_bots/zulip_bots/bots/incident/incident.py
+++ b/zulip_bots/zulip_bots/bots/incident/incident.py
@@ -63,7 +63,7 @@ def start_new_incident(query: str, message: Dict[str, Any], bot_handler: BotHand
 def parse_answer(query: str) -> Tuple[str, str]:
     m = re.match(r"answer\s+(TICKET....)\s+(.)", query)
     if not m:
-        raise InvalidAnswerException()
+        raise InvalidAnswerException
 
     ticket_id = m.group(1)
 
@@ -74,7 +74,7 @@ def parse_answer(query: str) -> Tuple[str, str]:
 
     answer = m.group(2).upper()
     if answer not in "1234":
-        raise InvalidAnswerException()
+        raise InvalidAnswerException
 
     return (ticket_id, ANSWERS[answer])
 
diff --git a/zulip_bots/zulip_bots/bots/mention/mention.py b/zulip_bots/zulip_bots/bots/mention/mention.py
index 3935f4db..98668d17 100644
--- a/zulip_bots/zulip_bots/bots/mention/mention.py
+++ b/zulip_bots/zulip_bots/bots/mention/mention.py
@@ -116,13 +116,13 @@ class MentionHandler:
             alert_id = self.get_alert_id(keyword)
         except (TypeError, KeyError):
             # Usually triggered by invalid token or json parse error when account quote is finished.
-            raise MentionNoResponseException()
+            raise MentionNoResponseException
 
         try:
             mentions = self.get_mentions(alert_id)
         except (TypeError, KeyError):
             # Usually triggered by no response or json parse error when account quota is finished.
-            raise MentionNoResponseException()
+            raise MentionNoResponseException
 
         reply = "The most recent mentions of `" + keyword + "` on the web are: \n"
         for mention in mentions:
diff --git a/zulip_bots/zulip_bots/bots/trivia_quiz/trivia_quiz.py b/zulip_bots/zulip_bots/bots/trivia_quiz/trivia_quiz.py
index ebb8b9b2..8fb4463b 100644
--- a/zulip_bots/zulip_bots/bots/trivia_quiz/trivia_quiz.py
+++ b/zulip_bots/zulip_bots/bots/trivia_quiz/trivia_quiz.py
@@ -75,12 +75,12 @@ def start_new_quiz(message: Dict[str, Any], bot_handler: BotHandler) -> None:
 def parse_answer(query: str) -> Tuple[str, str]:
     m = re.match(r"answer\s+(Q...)\s+(.)", query)
     if not m:
-        raise InvalidAnswerException()
+        raise InvalidAnswerException
 
     quiz_id = m.group(1)
     answer = m.group(2).upper()
     if answer not in "ABCD":
-        raise InvalidAnswerException()
+        raise InvalidAnswerException
 
     return (quiz_id, answer)
 
@@ -98,10 +98,10 @@ def get_trivia_payload() -> Dict[str, Any]:
         data = requests.get(url)
 
     except requests.exceptions.RequestException:
-        raise NotAvailableException()
+        raise NotAvailableException
 
     if data.status_code != 200:
-        raise NotAvailableException()
+        raise NotAvailableException
 
     payload = data.json()
     return payload
diff --git a/zulip_bots/zulip_bots/bots/xkcd/xkcd.py b/zulip_bots/zulip_bots/bots/xkcd/xkcd.py
index 09cd44ab..fd92f608 100644
--- a/zulip_bots/zulip_bots/bots/xkcd/xkcd.py
+++ b/zulip_bots/zulip_bots/bots/xkcd/xkcd.py
@@ -104,7 +104,7 @@ def fetch_xkcd_query(mode: int, comic_id: Optional[str] = None) -> Dict[str, str
             latest = requests.get(LATEST_XKCD_URL)
 
             if latest.status_code != 200:
-                raise XkcdServerError()
+                raise XkcdServerError
 
             latest_id = latest.json()["num"]
             random_id = random.randint(1, latest_id)
@@ -118,9 +118,9 @@ def fetch_xkcd_query(mode: int, comic_id: Optional[str] = None) -> Dict[str, str
         fetched = requests.get(url)
 
         if fetched.status_code == 404:
-            raise XkcdNotFoundError()
+            raise XkcdNotFoundError
         elif fetched.status_code != 200:
-            raise XkcdServerError()
+            raise XkcdServerError
 
         xkcd_json = fetched.json()
     except requests.exceptions.ConnectionError:
diff --git a/zulip_bots/zulip_bots/test_lib.py b/zulip_bots/zulip_bots/test_lib.py
index a03cf0fe..58a8228a 100755
--- a/zulip_bots/zulip_bots/test_lib.py
+++ b/zulip_bots/zulip_bots/test_lib.py
@@ -51,7 +51,7 @@ class StubBotHandler:
         pass
 
     def quit(self, message: str = "") -> None:
-        raise self.BotQuitException()
+        raise self.BotQuitException
 
     def get_config_info(self, bot_name: str, optional: bool = False) -> Dict[str, str]:
         return {}
@@ -77,10 +77,10 @@ class DefaultTests:
     bot_name = ""
 
     def make_request_message(self, content: str) -> Dict[str, Any]:
-        raise NotImplementedError()
+        raise NotImplementedError
 
     def get_response(self, message: Dict[str, Any]) -> Dict[str, Any]:
-        raise NotImplementedError()
+        raise NotImplementedError
 
     def test_bot_usage(self) -> None:
         bot = get_bot_message_handler(self.bot_name)