diff --git a/tiatoolbox/tools/stainextract.py b/tiatoolbox/tools/stainextract.py
index 7fc15d418..c2629af0c 100644
--- a/tiatoolbox/tools/stainextract.py
+++ b/tiatoolbox/tools/stainextract.py
@@ -5,10 +5,10 @@
 import numpy as np
 from sklearn.decomposition import DictionaryLearning
 
+from tiatoolbox import logger
 from tiatoolbox.utils.misc import get_luminosity_tissue_mask
 from tiatoolbox.utils.transforms import rgb2od
 
-from tiatoolbox import logger
 
 def vectors_in_correct_direction(e_vectors: np.ndarray) -> np.ndarray:
     """Points the eigen vectors in the right direction.
@@ -241,8 +241,8 @@ class VahadaneExtractor:
 
     .. warning::
         Vahadane stain extraction/normalization algorithms are unstable
-        after the update to `dictionary learning` algorithm in 
-        scikit-learn > v0.23.0 (see issue #382). Please be advised and 
+        after the update to `dictionary learning` algorithm in
+        scikit-learn > v0.23.0 (see issue #382). Please be advised and
         consider using other stain extraction (normalization) algorithms.
 
     Args: