diff --git a/src/sonic-py-common/tests/device_info_test.py b/src/sonic-py-common/tests/device_info_test.py
index f3b14b0a5f..df94d147aa 100644
--- a/src/sonic-py-common/tests/device_info_test.py
+++ b/src/sonic-py-common/tests/device_info_test.py
@@ -9,6 +9,8 @@ else:
     # https://pypi.python.org/pypi/mock
     import mock
 
+import pytest
+
 from sonic_py_common import device_info
 
 
@@ -51,9 +53,12 @@ EXPECTED_GET_MACHINE_INFO_RESULT = {
 
 
 class TestDeviceInfo(object):
-    @classmethod
-    def setup_class(cls):
-        print("SETUP")
+    @pytest.fixture(scope="class", autouse=True)
+    def sanitize_environment(self):
+        # Clear environment variables, in case a variable is set in the test
+        # environment (e.g., PLATFORM) which could modify the behavior of sonic-py-common
+        with mock.patch.dict(os.environ, {}, clear=True):
+            yield
 
     def test_get_machine_info(self):
         with mock.patch("os.path.isfile") as mock_isfile:
diff --git a/src/sonic-py-common/tests/interface_test.py b/src/sonic-py-common/tests/interface_test.py
index bb90479733..5e5b81b040 100644
--- a/src/sonic-py-common/tests/interface_test.py
+++ b/src/sonic-py-common/tests/interface_test.py
@@ -4,10 +4,6 @@ import sys
 from sonic_py_common import interface
 
 class TestInterface(object):
-    @classmethod
-    def setup_class(cls):
-        print("SETUP")
-
     def test_get_interface_table_name(self):
         result = interface.get_interface_table_name("Ethernet0")
         assert result == "INTERFACE"
@@ -35,7 +31,3 @@ class TestInterface(object):
         assert result == "VLAN_INTERFACE"
         result = interface.get_port_table_name("Loopback0")
         assert result == "LOOPBACK_INTERFACE"
-
-    @classmethod
-    def teardown_class(cls):
-        print("TEARDOWN")