diff --git a/tests/test_oauth2client_clientsecrets.py b/tests/test_oauth2client_clientsecrets.py
new file mode 100644
index 0000000..8733777
--- /dev/null
+++ b/tests/test_oauth2client_clientsecrets.py
@@ -0,0 +1,80 @@
+# Copyright 2011 Google Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""Unit tests for oauth2client.clientsecrets."""
+
+__author__ = 'jcgregorio@google.com (Joe Gregorio)'
+
+
+import os
+import unittest
+import StringIO
+
+
+import oauth2client.clientsecrets as clientsecrets
+
+
+class OAuth2CredentialsTests(unittest.TestCase):
+
+  def setUp(self):
+    pass
+
+  def tearDown(self):
+    pass
+
+  def test_validate_error(self):
+    ERRORS = [
+      (None, 'Invalid'),
+      ('{}', 'Invalid'),
+      ('{"foo": {}}', 'Unknown'),
+      ('{"web": {}}', 'Missing'),
+      ('{"web": {"client_id": "dkkd"}}', 'Missing'),
+      ("""{
+         "web": {
+           "client_id": "[[CLIENT ID REQUIRED]]",
+           "client_secret": "[[CLIENT SECRET REQUIRED]]",
+           "redirect_uris": ["http://localhost:8080/oauth2callback"],
+           "auth_uri": "",
+           "token_uri": ""
+         }
+       }
+       """, 'Property'),
+      ]
+    for src, match in ERRORS:
+      # Test load(s)
+      try:
+        clientsecrets.loads(src)
+        self.fail(src + ' should not be a valid client_secrets file.')
+      except clientsecrets.InvalidClientSecretsError, e:
+        self.assertTrue(str(e).startswith(match))
+
+      # Test loads(fp)
+      try:
+        fp = StringIO.StringIO(src)
+        clientsecrets.load(fp)
+        self.fail(src + ' should not be a valid client_secrets file.')
+      except clientsecrets.InvalidClientSecretsError, e:
+        self.assertTrue(str(e).startswith(match))
+
+  def test_load_by_filename(self):
+    try:
+      clientsecrets.loadfile(os.path.join(__file__, '..',
+                             'afilethatisntthere.json'))
+      self.fail('should fail to load a missing client_secrets file.')
+    except clientsecrets.InvalidClientSecretsError, e:
+      self.assertTrue(str(e).startswith('File'))
+
+
+if __name__ == '__main__':
+  unittest.main()