diff --git a/python/chemiscope/structures/__init__.py b/python/chemiscope/structures/__init__.py
index 48cf1c696..107512e54 100644
--- a/python/chemiscope/structures/__init__.py
+++ b/python/chemiscope/structures/__init__.py
@@ -18,7 +18,7 @@
     ase_tensors_to_ellipsoids,
     ase_vectors_to_arrows,
 )
-from ._mda import (
+from ._mda import (  # noqa: F401
     _mda_to_json,
     _mda_valid_structures,
     _mda_list_atom_properties,
@@ -47,7 +47,7 @@ def _guess_adapter(frames):
     stk_frames, use_stk = _stk_valid_structures(frames)
     if use_stk:
         return stk_frames, "stk"
-    
+
     mda_frames, use_mda = _mda_valid_structures(frames)
     if use_mda:
         return mda_frames, "mda"
@@ -133,10 +133,11 @@ def extract_properties(frames, only=None, environments=None):
         raise RuntimeError(
             "stk molecules do not contain properties, you must manually provide them"
         )
-    
+
     elif adapter == "mda":
         raise RuntimeError(
-            "MDAnalysis molecules do not contain properties, you must manually provide them"
+            "MDAnalysis molecules do not contain properties, you"
+            "must manually provide them"
         )
 
     else:
diff --git a/python/chemiscope/structures/_mda.py b/python/chemiscope/structures/_mda.py
index 42323409d..028db74ff 100644
--- a/python/chemiscope/structures/_mda.py
+++ b/python/chemiscope/structures/_mda.py
@@ -8,7 +8,7 @@
     HAVE_MDA = False
 
 
-def _mda_valid_structures(frames: mda.Universe):
+def _mda_valid_structures(frames):
     if HAVE_MDA and isinstance(frames, mda.Universe):
         return frames, True
     else:
@@ -25,7 +25,8 @@ def _mda_to_json(ag):
     if ag.dimensions is not None:
         data["cell"] = list(
             np.concatenate(
-                mda.lib.mdamath.triclinic_vectors(ag.dimensions), dtype=np.float64
+                mda.lib.mdamath.triclinic_vectors(ag.dimensions),
+                dtype=np.float64,
                 # should be np.float64 otherwise not serializable
             )
         )
diff --git a/python/tests/mda_structures.py b/python/tests/mda_structures.py
index a4fee8bb3..dde98d1cc 100644
--- a/python/tests/mda_structures.py
+++ b/python/tests/mda_structures.py
@@ -10,7 +10,6 @@
 BASE_FRAME.atoms.positions = np.array([[0, 0, 0], [1, 1, 1], [2, 2, 5]])
 
 
-
 class TestStructures(unittest.TestCase):
     """Conversion of structure data to chemiscope JSON"""
 
diff --git a/tox.ini b/tox.ini
index a3099cbfb..01855859d 100644
--- a/tox.ini
+++ b/tox.ini
@@ -29,6 +29,7 @@ deps =
     ase==3.22.1
     rdkit==2024.3.4
     stk
+    MDAnalysis
 
 commands =
     pip install chemiscope[explore]