diff --git a/src/_zkapauthorizer/tests/json.py b/src/_zkapauthorizer/tests/json.py
new file mode 100644
index 0000000000000000000000000000000000000000..e96cc74bbd830ccf7af0ad52882143bd9824594c
--- /dev/null
+++ b/src/_zkapauthorizer/tests/json.py
@@ -0,0 +1,36 @@
+# Copyright 2019 PrivateStorage.io, LLC
+#
+# 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.
+
+"""
+A better JSON module.
+"""
+
+from __future__ import (
+    absolute_import,
+)
+
+from json import (
+    loads as _loads,
+)
+
+def loads(data):
+    """
+    Load a JSON object from a byte string.
+
+    Raise an exception including ``data`` if the parse fails.
+    """
+    try:
+        return _loads(data)
+    except ValueError as e:
+        raise ValueError("{!r}: {!r}".format(e, data))