diff --git a/core/Constants.py b/core/Constants.py
index db34024..ec71cca 100644
--- a/core/Constants.py
+++ b/core/Constants.py
@@ -6,7 +6,8 @@ import os
 @dataclass(frozen=True)
 class Constants:
 
-    CLIENT_VERSION: Final[str] = '1.0.0'
+    SP_CLIENT_VERSION: Final[str] = '1.0.0'
+
     HOME: Final[str] = os.path.expanduser('~')
 
     CONFIG_HOME: Final[str] = os.environ.get('XDG_CONFIG_HOME') or os.path.join(HOME, '.config')
@@ -24,6 +25,6 @@ class Constants:
 
     SP_SESSION_STATE_HOME: Final[str] = SP_STATE_HOME + '/sessions'
 
-    SP_STORAGE_DATABASE: Final[str] = SP_DATA_HOME + '/storage.db'
+    SP_STORAGE_DATABASE_PATH: Final[str] = SP_DATA_HOME + '/storage.db'
 
     SP_API_BASE_URL: Final[str] = 'https://api.simplifiedprivacy.is/api/v1'
diff --git a/core/controllers/ApplicationVersionController.py b/core/controllers/ApplicationVersionController.py
index 9f48d15..4e35d88 100644
--- a/core/controllers/ApplicationVersionController.py
+++ b/core/controllers/ApplicationVersionController.py
@@ -37,7 +37,7 @@ class ApplicationVersionController:
         applications = ApplicationController.get_all()
         application_versions = []
 
-        for application_code in [application.code for application in applications]:
+        for application_code in (application.code for application in applications):
 
             application_version_subset = WebServiceApiService.get_application_versions(application_code, proxies)
 
diff --git a/core/controllers/ClientController.py b/core/controllers/ClientController.py
index 22197fa..73cbba9 100644
--- a/core/controllers/ClientController.py
+++ b/core/controllers/ClientController.py
@@ -21,7 +21,7 @@ class ClientController:
 
     @staticmethod
     def get_version():
-        return ClientVersionController.get(Constants.CLIENT_VERSION)
+        return ClientVersionController.get(Constants.SP_CLIENT_VERSION)
 
     @staticmethod
     def can_be_updated():
diff --git a/core/controllers/ConfigurationController.py b/core/controllers/ConfigurationController.py
index 27c7eb1..5dfde4b 100644
--- a/core/controllers/ConfigurationController.py
+++ b/core/controllers/ConfigurationController.py
@@ -25,7 +25,7 @@ class ConfigurationController:
 
         configuration = ConfigurationController.get()
 
-        if configuration is None or configuration.connection not in ['system', 'tor']:
+        if configuration is None or configuration.connection not in ('system', 'tor'):
             raise UnknownConnectionTypeError('The preferred connection type could not be determined.')
 
         return configuration.connection
diff --git a/core/controllers/ConnectionController.py b/core/controllers/ConnectionController.py
index 1419aee..b617e79 100644
--- a/core/controllers/ConnectionController.py
+++ b/core/controllers/ConnectionController.py
@@ -89,12 +89,12 @@ class ConnectionController:
 
         if profile.connection.is_unprotected():
 
-                if not ConnectionController.system_uses_wireguard_interface():
+            if not ConnectionController.system_uses_wireguard_interface():
 
-                    if not force:
-                        raise ConnectionUnprotectedError('Connection unprotected while the system is not using a WireGuard interface.')
-                    else:
-                        ProfileController.disable(profile)
+                if not force:
+                    raise ConnectionUnprotectedError('Connection unprotected while the system is not using a WireGuard interface.')
+                else:
+                    ProfileController.disable(profile)
 
         if profile.connection.code == 'tor':
 
diff --git a/core/controllers/ProfileController.py b/core/controllers/ProfileController.py
index 171505f..8c9a3d0 100644
--- a/core/controllers/ProfileController.py
+++ b/core/controllers/ProfileController.py
@@ -86,13 +86,13 @@ class ProfileController:
 
         if profile.is_system_profile():
 
-            profiles = ProfileController.get_all()
+            subjects = ProfileController.get_all().values()
 
-            for key, value in profiles.items():
+            for subject in subjects:
 
-                if type(value).__name__ == 'SessionProfile':
+                if subject.is_session_profile():
 
-                    if value.connection.is_unprotected() and ProfileController.is_enabled(value) and not force:
+                    if subject.connection.is_unprotected() and ProfileController.is_enabled(subject) and not force:
                         raise ConnectionUnprotectedError('Disabling this system connection would leave one or more sessions exposed.')
 
             if SystemStateController.exists():
@@ -174,7 +174,7 @@ class ProfileController:
     @staticmethod
     def attach_proxy_configuration(profile: Union[SessionProfile, SystemProfile]):
 
-        if type(profile).__name__ != 'SessionProfile':
+        if not profile.is_session_profile():
             return None
 
         if profile.subscription is None:
@@ -188,7 +188,7 @@ class ProfileController:
     @staticmethod
     def get_proxy_configuration(profile: Union[SessionProfile, SystemProfile]):
 
-        if type(profile).__name__ != 'SessionProfile':
+        if not profile.is_session_profile():
             return None
 
         profile.get_proxy_configuration()
diff --git a/core/models/Model.py b/core/models/Model.py
index 69f6af5..370d760 100644
--- a/core/models/Model.py
+++ b/core/models/Model.py
@@ -7,7 +7,7 @@ class Model:
     @staticmethod
     def _create_table_if_not_exists(table_name: str, table_definition: str, drop_existing: bool = False):
 
-        connection = sqlite3.connect(Constants.SP_STORAGE_DATABASE)
+        connection = sqlite3.connect(Constants.SP_STORAGE_DATABASE_PATH)
         cursor = connection.cursor()
 
         if drop_existing:
@@ -24,7 +24,7 @@ class Model:
         if parameters is None:
             parameters = []
 
-        connection = sqlite3.connect(Constants.SP_STORAGE_DATABASE)
+        connection = sqlite3.connect(Constants.SP_STORAGE_DATABASE_PATH)
         cursor = connection.cursor()
 
         cursor.row_factory = row_factory
@@ -37,7 +37,7 @@ class Model:
     @staticmethod
     def _query_exists(query: str, parameters):
 
-        connection = sqlite3.connect(Constants.SP_STORAGE_DATABASE)
+        connection = sqlite3.connect(Constants.SP_STORAGE_DATABASE_PATH)
         cursor = connection.cursor()
 
         response = cursor.execute('SELECT EXISTS(' + query + ')', parameters).fetchone()
@@ -51,7 +51,7 @@ class Model:
         if parameters is None:
             parameters = []
 
-        connection = sqlite3.connect(Constants.SP_STORAGE_DATABASE)
+        connection = sqlite3.connect(Constants.SP_STORAGE_DATABASE_PATH)
         cursor = connection.cursor()
 
         cursor.row_factory = row_factory
@@ -64,7 +64,7 @@ class Model:
     @staticmethod
     def _insert_many(query: str, tuple_factory, items):
 
-        connection = sqlite3.connect(Constants.SP_STORAGE_DATABASE)
+        connection = sqlite3.connect(Constants.SP_STORAGE_DATABASE_PATH)
         cursor = connection.cursor()
 
         cursor.executemany(query, map(tuple_factory, items))
diff --git a/core/models/Subscription.py b/core/models/Subscription.py
index a7247f2..801706c 100644
--- a/core/models/Subscription.py
+++ b/core/models/Subscription.py
@@ -22,7 +22,7 @@ class Subscription:
     )
 
     def is_active(self):
-        return self.expires_at is not None and self.expires_at > datetime.now(tz=timezone.utc)
+        return self.expires_at is not None and self.expires_at > datetime.now(timezone.utc)
 
     @staticmethod
     def from_iso_format(datetime_string: str):
diff --git a/core/models/SubscriptionPlan.py b/core/models/SubscriptionPlan.py
index 1281770..2b6262b 100644
--- a/core/models/SubscriptionPlan.py
+++ b/core/models/SubscriptionPlan.py
@@ -38,7 +38,7 @@ class SubscriptionPlan(Model):
         features_proxy = False
         features_wireguard = False
 
-        if type(connection).__name__ == 'SessionConnection':
+        if connection.is_session_connection():
             if connection.masked:
                 features_proxy = True
 
@@ -61,7 +61,7 @@ class SubscriptionPlan(Model):
             features_proxy = False
             features_wireguard = False
 
-            if type(connection).__name__ == 'SessionConnection':
+            if connection.is_session_connection():
                 if connection.masked:
                     features_proxy = True
 
diff --git a/main.py b/main.py
index 0642f85..4b7e800 100644
--- a/main.py
+++ b/main.py
@@ -172,7 +172,7 @@ if __name__ == '__main__':
 
                     manage_subscription_input = None
 
-                    while manage_subscription_input not in ['1', '2', '3', '']:
+                    while manage_subscription_input not in ('1', '2', '3', ''):
 
                         print('Please select from the following:\n')