diff --git a/management/backup.py b/management/backup.py
index 3b6b75cf..93744d7d 100755
--- a/management/backup.py
+++ b/management/backup.py
@@ -581,7 +581,7 @@ def get_backup_config(env, for_save=False, for_ui=False):
 	try:
 		with open(os.path.join(backup_root, 'custom.yaml')) as f:
 			custom_config = rtyaml.load(f)
-		if not isinstance(custom_config, dict): raise ValueError() # caught below
+		if not isinstance(custom_config, dict): raise ValueError # caught below
 		config.update(custom_config)
 	except:
 		pass
diff --git a/management/dns_update.py b/management/dns_update.py
index 16a589c2..e911135f 100755
--- a/management/dns_update.py
+++ b/management/dns_update.py
@@ -817,7 +817,7 @@ def get_custom_dns_config(env, only_real_records=False):
 	try:
 		with open(os.path.join(env['STORAGE_ROOT'], 'dns/custom.yaml')) as f:
 			custom_dns = rtyaml.load(f)
-		if not isinstance(custom_dns, dict): raise ValueError() # caught below
+		if not isinstance(custom_dns, dict): raise ValueError # caught below
 	except:
 		return [ ]
 
@@ -835,7 +835,7 @@ def get_custom_dns_config(env, only_real_records=False):
 
 		# No other type of data is allowed.
 		else:
-			raise ValueError()
+			raise ValueError
 
 		for rtype, value2 in values:
 			if isinstance(value2, str):
@@ -845,7 +845,7 @@ def get_custom_dns_config(env, only_real_records=False):
 					yield (qname, rtype, value3)
 			# No other type of data is allowed.
 			else:
-				raise ValueError()
+				raise ValueError
 
 def filter_custom_records(domain, custom_dns_iter):
 	for qname, rtype, value in custom_dns_iter:
diff --git a/management/utils.py b/management/utils.py
index 4ee100f1..f126f66b 100644
--- a/management/utils.py
+++ b/management/utils.py
@@ -38,7 +38,7 @@ def load_settings(env):
     try:
         with open(fn) as f:
             config = rtyaml.load(f)
-        if not isinstance(config, dict): raise ValueError() # caught below
+        if not isinstance(config, dict): raise ValueError # caught below
         return config
     except:
         return { }
diff --git a/tests/fail2ban.py b/tests/fail2ban.py
index bf002160..239eea23 100644
--- a/tests/fail2ban.py
+++ b/tests/fail2ban.py
@@ -33,7 +33,7 @@ def smtp_test():
 		server = smtplib.SMTP(hostname, 587)
 	except ConnectionRefusedError:
 		# looks like fail2ban worked
-		raise IsBlocked()
+		raise IsBlocked
 	server.starttls()
 	server.ehlo_or_helo_if_needed()
 
@@ -58,7 +58,7 @@ def imap_test():
 		M = imaplib.IMAP4_SSL(hostname)
 	except ConnectionRefusedError:
 		# looks like fail2ban worked
-		raise IsBlocked()
+		raise IsBlocked
 
 	try:
 		M.login("fakeuser", "fakepassword")
@@ -77,7 +77,7 @@ def pop_test():
 		M = poplib.POP3_SSL(hostname)
 	except ConnectionRefusedError:
 		# looks like fail2ban worked
-		raise IsBlocked()
+		raise IsBlocked
 	try:
 		M.user('fakeuser')
 		try:
@@ -102,7 +102,7 @@ def managesieve_test():
 		M = imaplib.IMAP4(hostname, 4190)
 	except ConnectionRefusedError:
 		# looks like fail2ban worked
-		raise IsBlocked()
+		raise IsBlocked
 
 	try:
 		M.login("fakeuser", "fakepassword")
@@ -134,10 +134,10 @@ def http_test(url, expected_status, postdata=None, qsargs=None, auth=None):
 			timeout=8,
 			verify=False) # don't bother with HTTPS validation, it may not be configured yet
 	except requests.exceptions.ConnectTimeout:
-		raise IsBlocked()
+		raise IsBlocked
 	except requests.exceptions.ConnectionError as e:
 		if "Connection refused" in str(e):
-			raise IsBlocked()
+			raise IsBlocked
 		raise # some other unexpected condition
 
 	# return response status code