diff --git a/python/sklearnserver/custom_transformer/__init__.py b/python/sklearnserver/custom_transformer/__init__.py
index eeb8126a230..d6af456a3c4 100644
--- a/python/sklearnserver/custom_transformer/__init__.py
+++ b/python/sklearnserver/custom_transformer/__init__.py
@@ -12,4 +12,4 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from .custom_transformer import DictToDFTransformer
+from .custom_transformer import DictToDFTransformer # noqa # pylint: disable=unused-import
diff --git a/python/sklearnserver/custom_transformer/custom_transformer.py b/python/sklearnserver/custom_transformer/custom_transformer.py
index 8916fa125d1..5e4ce103bc7 100644
--- a/python/sklearnserver/custom_transformer/custom_transformer.py
+++ b/python/sklearnserver/custom_transformer/custom_transformer.py
@@ -1,10 +1,25 @@
+# Copyright 2021 The KServe Authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
 import pandas as pd
 from sklearn.base import TransformerMixin
 
+
 class DictToDFTransformer(TransformerMixin):
 
-  def transform(self, X, y = None):
-    return pd.DataFrame(X)
-    
-  def fit(self, X, y = None):
-    return self
+    def transform(self, X, y = None):
+        return pd.DataFrame(X)
+
+    def fit(self, X, y = None):
+        return self
diff --git a/python/sklearnserver/setup.py b/python/sklearnserver/setup.py
index 82ca6ba0d38..f665b13758d 100644
--- a/python/sklearnserver/setup.py
+++ b/python/sklearnserver/setup.py
@@ -34,7 +34,8 @@
     install_requires=[
         "kserve>=0.7.0",
         "scikit-learn == 1.0.1",
-        "joblib >= 0.13.0"
+        "joblib >= 0.13.0",
+        "pandas >= 1.3.5"
     ],
     tests_require=tests_require,
     extras_require={'test': tests_require}
diff --git a/python/sklearnserver/sklearnserver/test_model.py b/python/sklearnserver/sklearnserver/test_model.py
index c0ad2d6e266..0051044dc58 100644
--- a/python/sklearnserver/sklearnserver/test_model.py
+++ b/python/sklearnserver/sklearnserver/test_model.py
@@ -63,7 +63,9 @@ def test_model_joblib():
 def test_multi_datatype_model_joblib():
     model = SKLearnModel("model", MULTI_DATATYPE_DIR)
     model.load()
-    request = [{'MSZoning': 'RL', 'LotArea': 8450, 'LotShape': 'Reg', 'Utilities': 'AllPub', 'YrSold': 2008, 'Neighborhood': 'CollgCr', 'OverallQual': 7, 'YearBuilt': 2003, 'SaleType': 'WD', 'GarageArea': 548}]
+    request = [{'MSZoning': 'RL', 'LotArea': 8450, 'LotShape': 'Reg', 'Utilities': 'AllPub',
+                'YrSold': 2008, 'Neighborhood': 'CollgCr', 'OverallQual': 7, 'YearBuilt': 2003,
+                'SaleType': 'WD', 'GarageArea': 548}]
     response = model.predict({"instances": request})
     assert response["predictions"] == [12.202832815138274]