diff --git a/plinth/errors.py b/plinth/errors.py
index cfd6746d4..32d4387f8 100644
--- a/plinth/errors.py
+++ b/plinth/errors.py
@@ -6,17 +6,14 @@ Project specific errors
 
 class PlinthError(Exception):
     """Base class for all FreedomBox specific errors."""
-    pass
 
 
 class ActionError(PlinthError):
     """Use this error for exceptions when executing an action."""
-    pass
 
 
 class PackageNotInstalledError(PlinthError):
     """Could not complete module setup due to missing package."""
-    pass
 
 
 class DomainNotRegisteredError(PlinthError):
@@ -24,7 +21,6 @@ class DomainNotRegisteredError(PlinthError):
     An action couldn't be performed because this
     FreedomBox doesn't have a registered domain
     """
-    pass
 
 
 class MissingPackageError(PlinthError):
diff --git a/plinth/modules/backups/api.py b/plinth/modules/backups/api.py
index 599d885ff..336ad1948 100644
--- a/plinth/modules/backups/api.py
+++ b/plinth/modules/backups/api.py
@@ -229,7 +229,6 @@ def _lockdown_apps(components, lockdown):
 
 def _is_snapshot_available():
     """Return whether it is possible to take filesystem snapshots."""
-    pass
 
 
 def _take_snapshot():
diff --git a/plinth/modules/firewall/__init__.py b/plinth/modules/firewall/__init__.py
index dacb29e57..1fbe71435 100644
--- a/plinth/modules/firewall/__init__.py
+++ b/plinth/modules/firewall/__init__.py
@@ -131,10 +131,8 @@ def ignore_dbus_error(dbus_error=None, service_error=None):
         if (dbus_error and parts[1].strip()
                 == 'org.freedesktop.DBus.Error.' + dbus_error):
             logger.error('Firewalld is not running.')
-            pass
         elif (service_error and parts[2].strip() == service_error):
             logger.warning('Ignoring firewall exception: %s', service_error)
-            pass
         else:
             raise
 
diff --git a/plinth/network.py b/plinth/network.py
index ac6296490..d2efa1a9b 100644
--- a/plinth/network.py
+++ b/plinth/network.py
@@ -33,12 +33,10 @@ CONNECTION_TYPE_NAMES = collections.OrderedDict([
 
 class ConnectionNotFound(Exception):
     """Network connection with a given name could not be found."""
-    pass
 
 
 class DeviceNotFound(Exception):
     """Network device for specified operation could not be found."""
-    pass
 
 
 def ipv4_string_to_int(address):