diff --git a/smdt/descriptors/kappa.py b/smdt/descriptors/kappa.py
index 838e90b..dbb4794 100644
--- a/smdt/descriptors/kappa.py
+++ b/smdt/descriptors/kappa.py
@@ -1,7 +1,10 @@
 
 from rdkit import Chem
 from rdkit.Chem import rdchem
-from rdkit.Chem import pyPeriodicTable as PeriodicTable
+try:
+    from rdkit.Chem import pyPeriodicTable as PeriodicTable
+except:
+    from rdkit.Chem import PeriodicTable
 periodicTable = rdchem.GetPeriodicTable()
 import pandas as pd
 
diff --git a/smdt/regression.py b/smdt/regression.py
index ec16bcc..45f3e20 100644
--- a/smdt/regression.py
+++ b/smdt/regression.py
@@ -1,5 +1,9 @@
 from sklearn.ensemble import RandomForestRegressor
-from sklearn.preprocessing import StandardScaler, LabelEncoder, Imputer
+from sklearn.preprocessing import StandardScaler, LabelEncoder
+try:
+    from sklearn.preprocessing import Imputer
+except ImportError:
+    from sklearn.impute import SimpleImputer
 from sklearn.feature_selection import SelectKBest, mutual_info_regression
 from sklearn.model_selection import train_test_split, GridSearchCV
 from sklearn.linear_model import LassoCV, RidgeCV, ElasticNetCV