diff --git a/selfprivacy_api/actions/system.py b/selfprivacy_api/actions/system.py
index 4c40ae7..7957f77 100644
--- a/selfprivacy_api/actions/system.py
+++ b/selfprivacy_api/actions/system.py
@@ -46,12 +46,12 @@ class UserDataAutoUpgradeSettings(BaseModel):
 
 def set_dns_provider(provider: DnsProvider, token: str):
     with WriteUserData() as user_data:
-        if not "dns" in user_data.keys():
+        if "dns" not in user_data.keys():
             user_data["dns"] = {}
         user_data["dns"]["provider"] = provider.value
 
     with WriteUserData(file_type=UserDataFiles.SECRETS) as secrets:
-        if not "dns" in secrets.keys():
+        if "dns" not in secrets.keys():
             secrets["dns"] = {}
         secrets["dns"]["apiKey"] = token
 
diff --git a/selfprivacy_api/graphql/mutations/system_mutations.py b/selfprivacy_api/graphql/mutations/system_mutations.py
index c304cc7..49aba36 100644
--- a/selfprivacy_api/graphql/mutations/system_mutations.py
+++ b/selfprivacy_api/graphql/mutations/system_mutations.py
@@ -15,7 +15,6 @@ from selfprivacy_api.graphql.mutations.mutation_interface import (
     GenericJobMutationReturn,
     GenericMutationReturn,
     MutationReturnInterface,
-    GenericJobMutationReturn,
 )
 
 import selfprivacy_api.actions.system as system_actions