diff --git a/sksurv/functions.py b/sksurv/functions.py
index ee978cc8..154f0f75 100644
--- a/sksurv/functions.py
+++ b/sksurv/functions.py
@@ -12,7 +12,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 import numpy as np
-from sklearn.utils import check_consistent_length
+from sklearn.utils.validation import check_consistent_length
 
 __all__ = ["StepFunction"]
 
diff --git a/sksurv/metrics.py b/sksurv/metrics.py
index d797607d..af6bc4d6 100644
--- a/sksurv/metrics.py
+++ b/sksurv/metrics.py
@@ -12,9 +12,8 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 import numpy as np
 from sklearn.base import BaseEstimator
-from sklearn.utils import check_array, check_consistent_length
 from sklearn.utils.metaestimators import available_if
-from sklearn.utils.validation import check_is_fitted
+from sklearn.utils.validation import check_array, check_consistent_length, check_is_fitted
 
 from .exceptions import NoComparablePairException
 from .nonparametric import CensoringDistributionEstimator, SurvivalFunctionEstimator
diff --git a/sksurv/svm/naive_survival_svm.py b/sksurv/svm/naive_survival_svm.py
index c46d0bdc..26d6c7da 100644
--- a/sksurv/svm/naive_survival_svm.py
+++ b/sksurv/svm/naive_survival_svm.py
@@ -16,8 +16,7 @@
 import pandas as pd
 from scipy.special import comb
 from sklearn.svm import LinearSVC
-from sklearn.utils import check_random_state
-from sklearn.utils.validation import _get_feature_names, validate_data
+from sklearn.utils.validation import _get_feature_names, check_random_state, validate_data
 
 from ..base import SurvivalAnalysisMixin
 from ..exceptions import NoComparablePairException
diff --git a/sksurv/util.py b/sksurv/util.py
index 1580d901..87e2a73e 100644
--- a/sksurv/util.py
+++ b/sksurv/util.py
@@ -13,7 +13,7 @@
 import numpy as np
 import pandas as pd
 from pandas.api.types import CategoricalDtype
-from sklearn.utils import check_array, check_consistent_length
+from sklearn.utils.validation import check_array, check_consistent_length
 
 __all__ = ["check_array_survival", "check_y_survival", "safe_concat", "Surv"]