diff --git a/sonic-chassisd/scripts/chassisd b/sonic-chassisd/scripts/chassisd
index d064f7e07e48..50b767725fbf 100644
--- a/sonic-chassisd/scripts/chassisd
+++ b/sonic-chassisd/scripts/chassisd
@@ -14,18 +14,16 @@ try:
 
     from sonic_py_common import daemon_base, logger
     from sonic_py_common.task_base import ProcessTaskBase
-except ImportError as e:
-    raise ImportError (str(e) + " - required module not found")
 
-try:
-    from swsscommon import swsscommon
+    # If unit testing is occurring, mock swsscommon and module_base
+    if os.environ["CHASSISD_UNIT_TESTING"] == "1":
+        from tests import mock_swsscommon as swsscommon
+        from tests.mock_module_base import ModuleBase
+    else:
+        from swsscommon import swsscommon
+        from sonic_platform_base.module_base import ModuleBase
 except ImportError as e:
-    from tests import mock_swsscommon as swsscommon
-
-try:
-    from sonic_platform_base.module_base import ModuleBase
-except ImportError as e:
-    from tests.mock_module_base import ModuleBase
+    raise ImportError (str(e) + " - required module not found")
 
 #
 # Constants ====================================================================
diff --git a/sonic-chassisd/tests/test_chassisd.py b/sonic-chassisd/tests/test_chassisd.py
index 6684ea932257..ac2c6a0692af 100644
--- a/sonic-chassisd/tests/test_chassisd.py
+++ b/sonic-chassisd/tests/test_chassisd.py
@@ -1,5 +1,6 @@
 import os
 import sys
+from imp import load_source
 
 from mock import Mock, MagicMock, patch
 from sonic_py_common import daemon_base
@@ -17,10 +18,7 @@
 scripts_path = os.path.join(modules_path, "scripts")
 sys.path.insert(0, modules_path)
 
-from imp import load_source
 
-load_source('chassisd', scripts_path + '/chassisd')
-from chassisd import *
 
 CHASSIS_MODULE_INFO_NAME_FIELD = 'name'
 CHASSIS_MODULE_INFO_DESC_FIELD = 'desc'
@@ -31,6 +29,11 @@
 CHASSIS_INFO_CARD_NUM_FIELD = 'module_num'
 
 def setup_function():
+    os.environ["CHASSISD_UNIT_TESTING"] = "1"
+
+    load_source('chassisd', scripts_path + '/chassisd')
+    from chassisd import *
+
     ModuleUpdater.log_notice = MagicMock()
     ModuleUpdater.log_warning = MagicMock()
 
@@ -38,6 +41,7 @@ def setup_function():
 def teardown_function():
     ModuleUpdater.log_notice.reset()
     ModuleUpdater.log_warning.reset()
+    os.environ["CHASSISD_UNIT_TESTING"] = "0"
 
 
 def test_moduleupdater_check_valid_fields():
diff --git a/sonic-thermalctld/scripts/thermalctld b/sonic-thermalctld/scripts/thermalctld
index a746b218d08e..dd3b83a9d49a 100644
--- a/sonic-thermalctld/scripts/thermalctld
+++ b/sonic-thermalctld/scripts/thermalctld
@@ -13,13 +13,15 @@ try:
 
     from sonic_py_common import daemon_base, logger
     from sonic_py_common.task_base import ProcessTaskBase
+
+    # If unit testing is occurring, mock swsscommon
+    if os.environ["THERMALCTLD_UNIT_TESTING"] == "1":
+        from tests import mock_swsscommon as swsscommon
+    else:
+        from swsscommon import swsscommon
 except ImportError as e:
     raise ImportError(repr(e) + " - required module not found")
 
-try:
-    from swsscommon import swsscommon
-except ImportError as e:
-    from tests import mock_swsscommon as swsscommon
 
 SYSLOG_IDENTIFIER = 'thermalctld'
 NOT_AVAILABLE = 'N/A'
diff --git a/sonic-thermalctld/tests/test_thermalctld.py b/sonic-thermalctld/tests/test_thermalctld.py
index 15344bdea5a9..236b6c2ba206 100644
--- a/sonic-thermalctld/tests/test_thermalctld.py
+++ b/sonic-thermalctld/tests/test_thermalctld.py
@@ -1,5 +1,6 @@
 import os
 import sys
+from imp import load_source
 
 from mock import Mock, MagicMock, patch
 from sonic_py_common import daemon_base
@@ -16,14 +17,15 @@
 scripts_path = os.path.join(modules_path, "scripts")
 sys.path.insert(0, modules_path)
 
-from imp import load_source
-
-load_source('thermalctld', scripts_path + '/thermalctld')
-from thermalctld import *
 
 TEMPER_INFO_TABLE_NAME = 'TEMPERATURE_INFO'
 
 def setup_function():
+    os.environ["THERMALCTLD_UNIT_TESTING"] = "1"
+
+    load_source('thermalctld', scripts_path + '/thermalctld')
+    from thermalctld import *
+
     FanStatus.log_notice = MagicMock()
     FanStatus.log_warning = MagicMock()
     FanUpdater.log_notice = MagicMock()
@@ -43,6 +45,7 @@ def teardown_function():
     TemperatureStatus.log_warning.reset()
     TemperatureUpdater.log_warning.reset()
     TemperatureUpdater.log_warning.reset()
+    os.environ["THERMALCTLD_UNIT_TESTING"] = "0"
 
 
 def test_fanstatus_set_presence():