diff --git a/src/lerobot/datasets/video_utils.py b/src/lerobot/datasets/video_utils.py
index 5064d61f7..bb37bb225 100644
--- a/src/lerobot/datasets/video_utils.py
+++ b/src/lerobot/datasets/video_utils.py
@@ -37,11 +37,12 @@ import torchvision
 from datasets.features.features import register_feature
 from PIL import Image
 
+from lerobot.utils.import_utils import get_safe_default_video_backend
+
 from .pyav_utils import (
     check_video_encoder_config_pyav,
     detect_available_encoders_pyav,
 )
-from lerobot.utils.import_utils import get_safe_default_video_backend
 
 logger = logging.getLogger(__name__)
 
diff --git a/tests/datasets/test_video_encoding.py b/tests/datasets/test_video_encoding.py
index 968b3c5a3..7332ab357 100644
--- a/tests/datasets/test_video_encoding.py
+++ b/tests/datasets/test_video_encoding.py
@@ -478,7 +478,9 @@ class TestConcatenateVideoFiles:
     def test_two_clips_frame_count(self, tmp_path):
         """Output frame count equals the sum of the two input frame counts."""
         out = tmp_path / "out.mp4"
-        concatenate_video_files([TEST_ARTIFACTS_DIR / "clip_6frames.mp4", TEST_ARTIFACTS_DIR / "clip_4frames.mp4"], out)
+        concatenate_video_files(
+            [TEST_ARTIFACTS_DIR / "clip_6frames.mp4", TEST_ARTIFACTS_DIR / "clip_4frames.mp4"], out
+        )
 
         with av.open(str(out)) as container:
             total = sum(1 for _ in container.decode(video=0))
@@ -497,7 +499,9 @@ class TestConcatenateVideoFiles:
     def test_geometry_preserved(self, tmp_path):
         """Output resolution, fps, codec and pixel format must match the inputs."""
         out = tmp_path / "out.mp4"
-        concatenate_video_files([TEST_ARTIFACTS_DIR / "clip_4frames.mp4", TEST_ARTIFACTS_DIR / "clip_4frames.mp4"], out)
+        concatenate_video_files(
+            [TEST_ARTIFACTS_DIR / "clip_4frames.mp4", TEST_ARTIFACTS_DIR / "clip_4frames.mp4"], out
+        )
 
         info = get_video_info(out)
         assert info["video.height"] == 64