diff --git a/kubespawner/spawner.py b/kubespawner/spawner.py
index 5766ec32..327ee123 100644
--- a/kubespawner/spawner.py
+++ b/kubespawner/spawner.py
@@ -2061,7 +2061,9 @@ async def get_pod_manifest(self):
             pod_security_context=psc,
             env=self.get_env(),  # Expansion is handled by get_env
             volumes=self._expand_all(self._sorted_dict_values(self.volumes)),
-            volume_mounts=self._expand_all(self._sorted_dict_values(self.volume_mounts)),
+            volume_mounts=self._expand_all(
+                self._sorted_dict_values(self.volume_mounts)
+            ),
             working_dir=self.working_dir,
             labels=labels,
             annotations=annotations,
diff --git a/tests/test_spawner.py b/tests/test_spawner.py
index 314bfb02..7c3c7236 100644
--- a/tests/test_spawner.py
+++ b/tests/test_spawner.py
@@ -1880,7 +1880,9 @@ async def test_volume_dict():
 
     assert isinstance(manifest.spec.volumes, list)
     assert manifest.spec.volumes[0].name == 'volumes-alpha'
-    assert manifest.spec.volumes[0].persistent_volume_claim["claimName"] == 'alpha-claim'
+    assert (
+        manifest.spec.volumes[0].persistent_volume_claim["claimName"] == 'alpha-claim'
+    )
     assert manifest.spec.volumes[1].name == 'volumes-beta'
     assert manifest.spec.volumes[1].persistent_volume_claim["claimName"] == 'beta-claim'
 
@@ -1907,6 +1909,8 @@ async def test_volume_list():
 
     assert isinstance(manifest.spec.volumes, list)
     assert manifest.spec.volumes[0].name == 'volumes-alpha'
-    assert manifest.spec.volumes[0].persistent_volume_claim["claimName"] == 'alpha-claim'
+    assert (
+        manifest.spec.volumes[0].persistent_volume_claim["claimName"] == 'alpha-claim'
+    )
     assert manifest.spec.volumes[1].name == 'volumes-beta'
     assert manifest.spec.volumes[1].persistent_volume_claim["claimName"] == 'beta-claim'