diff --git a/unit_tests/__init__.py b/unit_tests/__init__.py
index e24a5b3..21a9870 100644
--- a/unit_tests/__init__.py
+++ b/unit_tests/__init__.py
@@ -1,5 +1,6 @@
 import os
 import sys
+from unittest.mock import patch
 
 _path = os.path.dirname(os.path.realpath(__file__))
 _actions = os.path.abspath(os.path.join(_path, '../actions'))
@@ -17,3 +18,16 @@ _add_path(_actions)
 _add_path(_hooks)
 _add_path(_charmhelpers)
 _add_path(_unit_tests)
+
+
+# Patch out lsb_release() and get_platform() as unit tests should be fully
+# insulated from the underlying platform.  Unit tests assume that the system is
+# ubuntu jammy.
+patch(
+    'charmhelpers.osplatform.get_platform', return_value='ubuntu'
+).start()
+patch(
+    'charmhelpers.core.host.lsb_release',
+    return_value={
+        'DISTRIB_CODENAME': 'jammy'
+    }).start()