diff --git a/bob/bio/gmm/algorithm/GMM.py b/bob/bio/gmm/algorithm/GMM.py
index 423fbc516e32fdcc4b53c66b874827bddfec2470..a122da9bf79cde683ddcf6819afbe9cf1037818e 100644
--- a/bob/bio/gmm/algorithm/GMM.py
+++ b/bob/bio/gmm/algorithm/GMM.py
@@ -13,8 +13,8 @@ This adds the notions of models, probes, enrollment, and scores to GMM.
 import copy
 import logging
 
-from typing import Union
 from typing import Callable
+from typing import Union
 
 import dask
 import dask.array as da
@@ -24,9 +24,9 @@ from h5py import File as HDF5File
 from sklearn.base import BaseEstimator
 
 from bob.bio.base.pipelines.vanilla_biometrics.abstract_classes import BioAlgorithm
-from bob.learn.em import KMeansMachine
 from bob.learn.em import GMMMachine
 from bob.learn.em import GMMStats
+from bob.learn.em import KMeansMachine
 from bob.learn.em import linear_scoring
 
 logger = logging.getLogger(__name__)
@@ -50,7 +50,9 @@ class GMM(BioAlgorithm, BaseEstimator):
         number_of_gaussians: int,
         # parameters of UBM training
         kmeans_training_iterations: int = 25,  # Maximum number of iterations for K-Means
-        kmeans_init_iterations: Union[int,None] = None,  # Maximum number of iterations for K-Means init
+        kmeans_init_iterations: Union[
+            int, None
+        ] = None,  # Maximum number of iterations for K-Means init
         kmeans_oversampling_factor: int = 64,
         ubm_training_iterations: int = 25,  # Maximum number of iterations for GMM Training
         training_threshold: float = 5e-4,  # Threshold to end the ML training
@@ -117,7 +119,11 @@ class GMM(BioAlgorithm, BaseEstimator):
         # Copy parameters
         self.number_of_gaussians = number_of_gaussians
         self.kmeans_training_iterations = kmeans_training_iterations
-        self.kmeans_init_iterations = kmeans_training_iterations if kmeans_init_iterations is None else kmeans_init_iterations
+        self.kmeans_init_iterations = (
+            kmeans_training_iterations
+            if kmeans_init_iterations is None
+            else kmeans_init_iterations
+        )
         self.kmeans_oversampling_factor = kmeans_oversampling_factor
         self.ubm_training_iterations = ubm_training_iterations
         self.training_threshold = training_threshold
diff --git a/bob/bio/gmm/test/test_gmm.py b/bob/bio/gmm/test/test_gmm.py
index 4a9acb404149b5060a3af453e74dc21a63d89008..0c9f126a3c9162e9cc32afb7f198f526860ab51f 100644
--- a/bob/bio/gmm/test/test_gmm.py
+++ b/bob/bio/gmm/test/test_gmm.py
@@ -18,7 +18,6 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 import logging
-import os
 import tempfile
 
 import numpy