diff --git a/tox.ini b/tox.ini
index 7a8acdd..858997b 100644
--- a/tox.ini
+++ b/tox.ini
@@ -13,9 +13,12 @@ deps = -r{toxinidir}/requirements.txt
 commands = stestr run --slowest {posargs}
 
 [testenv:linters]
+whitelist_externals = bash
 commands =
   # Check the *.rst files
   doc8 README.rst guidelines
+  # Check the JSON files
+  bash -c 'for f in guidelines/*.json; do echo Checking "$f"; python -m json.tool "$f" /dev/null || exit 1; done'
 
 [testenv:venv]
 commands = {posargs}