diff --git a/pytest.ini b/pytest.ini
index 0372271a..704c8b70 100644
--- a/pytest.ini
+++ b/pytest.ini
@@ -3,3 +3,4 @@ filterwarnings =
     error
     ignore::FutureWarning
     ignore::RuntimeWarning
+    ignore::DeprecationWarning
diff --git a/strlearn/tests/test_classifiers.py b/strlearn/tests/test_classifiers.py
index 346638a0..5d1ecebe 100644
--- a/strlearn/tests/test_classifiers.py
+++ b/strlearn/tests/test_classifiers.py
@@ -1,7 +1,5 @@
 """Classifier tests."""
 
-import sys
-
 from sklearn.naive_bayes import GaussianNB
 
 import strlearn as sl