diff --git a/studio/backend/tests/test_diffusion_backend.py b/studio/backend/tests/test_diffusion_backend.py
index 0f8b84f083..477577ba35 100644
--- a/studio/backend/tests/test_diffusion_backend.py
+++ b/studio/backend/tests/test_diffusion_backend.py
@@ -3030,8 +3030,8 @@ def test_unload_waits_for_in_flight_denoise_before_teardown():
         with backend._generate_lock:
             denoise_active["v"] = True
             started.set()
-            cancel.wait(2.0)   # unload signals this
-            finish.wait(2.0)   # the test lets us finish
+            cancel.wait(2.0)  # unload signals this
+            finish.wait(2.0)  # the test lets us finish
             denoise_active["v"] = False  # about to release _generate_lock
 
     def _fake_unload_locked():
diff --git a/studio/backend/tests/test_diffusion_engine_router.py b/studio/backend/tests/test_diffusion_engine_router.py
index 53d40a1336..4ff9bc23c7 100644
--- a/studio/backend/tests/test_diffusion_engine_router.py
+++ b/studio/backend/tests/test_diffusion_engine_router.py
@@ -258,9 +258,7 @@ def test_activate_serializes_switch_and_concurrent_query(monkeypatch):
         unload_started.set()
         release_unload.wait(2.0)
 
-    engine = SimpleNamespace(
-        status = lambda: {"loaded": False, "repo_id": None}, unload = _slow_unload
-    )
+    engine = SimpleNamespace(status = lambda: {"loaded": False, "repo_id": None}, unload = _slow_unload)
     monkeypatch.setattr(r, "get_active_diffusion_engine", lambda: engine)
 
     switch_done = threading.Event()
diff --git a/studio/backend/tests/test_diffusion_routes.py b/studio/backend/tests/test_diffusion_routes.py
index 6e6f7ea2da..34b4061fd0 100644
--- a/studio/backend/tests/test_diffusion_routes.py
+++ b/studio/backend/tests/test_diffusion_routes.py
@@ -180,7 +180,12 @@ def client(monkeypatch, tmp_path):
     monkeypatch.setattr(gallery_module, "save", _save)
     monkeypatch.setattr(gallery_module, "image_b64", lambda i: "QUJD" if i in store else None)
 
-    def _list_images(limit = None, offset = 0, *, valid = None):
+    def _list_images(
+        limit = None,
+        offset = 0,
+        *,
+        valid = None,
+    ):
         ordered = sorted(store.values(), key = lambda r: r.get("created_at", 0.0), reverse = True)
         if valid is not None:
             ordered = [r for r in ordered if valid(r)]