diff --git a/.github/workflows/linters.yaml b/.github/workflows/linters.yaml
index 0de0e33..2018b3a 100644
--- a/.github/workflows/linters.yaml
+++ b/.github/workflows/linters.yaml
@@ -22,6 +22,8 @@
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           VALIDATE_ALL_CODEBASE: true
           VALIDATE_DOCKERFILE_HADOLINT: false
+          VALIDATE_PYTHON_ISORT: false
+          VALIDATE_PYTHON_BLACK: false
           VALIDATE_PYTHON_MYPY: false
           VALIDATE_JSCPD: false
   pep8:
diff --git a/staffeln/common/openstack.py b/staffeln/common/openstack.py
index ea566e3..e9f730c 100644
--- a/staffeln/common/openstack.py
+++ b/staffeln/common/openstack.py
@@ -3,7 +3,6 @@
 from openstack import exceptions
 from openstack import proxy
 from oslo_log import log
-import tenacity
 
 from staffeln.common import auth
 from staffeln.i18n import _
diff --git a/staffeln/conductor/backup.py b/staffeln/conductor/backup.py
index 559d782..5319035 100755
--- a/staffeln/conductor/backup.py
+++ b/staffeln/conductor/backup.py
@@ -675,8 +675,8 @@
         except OpenstackHttpException as ex:
             LOG.warn(
                 _(
-                    "Failed to delete volume backup %s. %s. Need to delete manually."
-                    % (task.backup_id, str(ex))
+                    "Failed to delete volume backup %s. %s. Need "
+                    "to delete manually." % (task.backup_id, str(ex))
                 )
             )
         task.reason = reason