diff --git a/test/test_container_token_manager.py b/test/test_container_token_manager.py
index 97ea5f2..2c4b47d 100644
--- a/test/test_container_token_manager.py
+++ b/test/test_container_token_manager.py
@@ -14,6 +14,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+# DISCLAIMER: The JWT token strings used in this file are for testing purposes only.
+# They are not valid tokens and cannot be used to authenticate with any real service.
+
 # pylint: disable=missing-docstring
 import logging
 import json
diff --git a/test/test_iam_token_manager.py b/test/test_iam_token_manager.py
index 683bce9..e801903 100644
--- a/test/test_iam_token_manager.py
+++ b/test/test_iam_token_manager.py
@@ -14,6 +14,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+# DISCLAIMER: The JWT token strings used in this file are for testing purposes only.
+# They are not valid tokens and cannot be used to authenticate with any real service.
+
 # pylint: disable=missing-docstring
 import logging
 import os
diff --git a/test/test_vpc_instance_token_manager.py b/test/test_vpc_instance_token_manager.py
index 9fafdc9..1b2f86a 100644
--- a/test/test_vpc_instance_token_manager.py
+++ b/test/test_vpc_instance_token_manager.py
@@ -14,6 +14,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+# DISCLAIMER: The JWT token strings used in this file are for testing purposes only.
+# They are not valid tokens and cannot be used to authenticate with any real service.
+
 # pylint: disable=missing-docstring
 import json
 import logging