diff --git a/CI/circle_parallel.sh b/CI/circle_parallel.sh
index 697009699a3..74e5f018f1b 100755
--- a/CI/circle_parallel.sh
+++ b/CI/circle_parallel.sh
@@ -59,6 +59,7 @@ elif [ "$NODE_INDEX" = "3" ]; then
   #sudo make altinstall
   pyenv install --list 
   pyenv install 3.6.3
+  pyenv install 2.7.14
   pyenv global 3.6.3
   python3 --version
 
diff --git a/pom.xml b/pom.xml
index 318bf21f0dc..06a209e7458 100644
--- a/pom.xml
+++ b/pom.xml
@@ -1283,6 +1283,7 @@
                 <module>samples/client/petstore/python</module>
                 <module>samples/client/petstore/python_disallowAdditionalPropertiesIfNotPresent</module>
                 <module>samples/openapi3/client/petstore/python</module>
+                <module>samples/openapi3/client/petstore/python-legacy</module>
                 <!-- TODO comment out below when the test for typescript-nestjs is ready
                 <module>samples/client/petstore/typescript-nestjs-v6-provided-in-root</module>-->
                 <!-- comment out due to error `npm run build`
diff --git a/samples/openapi3/client/petstore/python-legacy/test/test_fake_api.py b/samples/openapi3/client/petstore/python-legacy/test/test_fake_api.py
index b7f11348897..a485b1f91c9 100644
--- a/samples/openapi3/client/petstore/python-legacy/test/test_fake_api.py
+++ b/samples/openapi3/client/petstore/python-legacy/test/test_fake_api.py
@@ -13,7 +13,10 @@
 from __future__ import absolute_import
 
 import unittest
-from unittest.mock import patch
+try:
+    from unittest.mock import patch
+except ImportError:
+    from mock import patch
 
 import petstore_api
 from petstore_api.api.fake_api import FakeApi  # noqa: E501
diff --git a/samples/openapi3/client/petstore/python-legacy/test_python2.sh b/samples/openapi3/client/petstore/python-legacy/test_python2.sh
index dbf254b0961..722b3ee5e23 100755
--- a/samples/openapi3/client/petstore/python-legacy/test_python2.sh
+++ b/samples/openapi3/client/petstore/python-legacy/test_python2.sh
@@ -20,6 +20,7 @@ fi
 pip install -r $REQUIREMENTS_FILE | tee -a $REQUIREMENTS_OUT
 
 ### run tests
+tox -l
 tox -e py27 || exit 1
 
 ### static analysis of code