diff --git a/nitransforms/tests/test_base.py b/nitransforms/tests/test_base.py
index f315cc6c..07a7e4ec 100644
--- a/nitransforms/tests/test_base.py
+++ b/nitransforms/tests/test_base.py
@@ -111,7 +111,7 @@ def _to_hdf5(klass, x5_root):
         imgdata == np.asanyarray(moved.dataobj, dtype=moved.get_data_dtype())
     )
 
-    #Test ndim returned by affine
+    # Test ndim returned by affine
     assert nitl.Affine().ndim == 3
     assert nitl.LinearTransformsMapping(
         [nitl.Affine(), nitl.Affine()]