diff --git a/art/defences/detector/poison/roni.py b/art/defences/detector/poison/roni.py
index 55877ad828..52372d0d53 100644
--- a/art/defences/detector/poison/roni.py
+++ b/art/defences/detector/poison/roni.py
@@ -25,7 +25,7 @@
 
 import logging
 from copy import deepcopy
-from typing import Any, Callable, List, Tuple, Union, TYPE_CHECKING
+from typing import Callable, List, Tuple, Union, TYPE_CHECKING
 
 import numpy as np
 from sklearn.model_selection import train_test_split
diff --git a/art/utils.py b/art/utils.py
index 83d057d152..eaa55f7948 100644
--- a/art/utils.py
+++ b/art/utils.py
@@ -1305,11 +1305,11 @@ def load_stl() -> DATASET_TYPE:
 
     with open(os.path.join(path, "train_y.bin"), "rb") as f_numpy:
         y_train = np.fromfile(f_numpy, dtype=np.uint8)
-        y_train -= 1
+        y_train = y_train - 1
 
     with open(os.path.join(path, "test_y.bin"), "rb") as f_numpy:
         y_test = np.fromfile(f_numpy, dtype=np.uint8)
-        y_test -= 1
+        y_test = y_test - 1
 
     x_train, y_train = preprocess(x_train, y_train)
     x_test, y_test = preprocess(x_test, y_test)
diff --git a/tests/attacks/evasion/test_auto_attack.py b/tests/attacks/evasion/test_auto_attack.py
index bfc70b2d58..86fa6b3769 100644
--- a/tests/attacks/evasion/test_auto_attack.py
+++ b/tests/attacks/evasion/test_auto_attack.py
@@ -196,7 +196,9 @@ def test_classifier_type_check_fail(art_warning):
 @pytest.mark.skip_framework("tensorflow1", "tensorflow2v1", "keras", "non_dl_frameworks", "mxnet", "kerastf")
 def test_generate_parallel(art_warning, fix_get_mnist_subset, image_dl_estimator):
     try:
+        import tensorflow as tf
         classifier, _ = image_dl_estimator(from_logits=True)
+        classifier.model.compile(optimizer=tf.keras.optimizers.Adam(learning_rate=0.01))
 
         norm = np.inf
         eps = 0.3