diff --git a/ops/charm.py b/ops/charm.py
index 99e1f2651..db02e13d9 100644
--- a/ops/charm.py
+++ b/ops/charm.py
@@ -668,7 +668,9 @@ def restore(self, snapshot: Dict[str, Any]):
 
         if storage_name and storage_index is not None:
             storages = self.framework.model.storages[storage_name]
-            self.storage = next((s for s in storages if s.index == storage_index), None)  # type: ignore
+            self.storage = next(
+                (s for s in storages if s.index == storage_index),
+                None)  # type: ignore
             if self.storage is None:
                 msg = 'failed loading storage (name={!r}, index={!r}) from snapshot' \
                     .format(storage_name, storage_index)
diff --git a/tox.ini b/tox.ini
index a5330ae56..15c1a46f8 100644
--- a/tox.ini
+++ b/tox.ini
@@ -36,9 +36,9 @@ commands =
 description = Apply coding style standards to code
 deps =
     autopep8~=1.6
-    isort~=5.11
+    isort~=5.13
 commands =
-    isort {[vars]all_path}
+    isort {[vars]all_path} --multi-line=3 --line-length=99 --split-on-trailing-comma
     autopep8 --in-place {[vars]all_path}
 
 [testenv:lint]