diff --git a/python/tox.ini b/python/tox.ini
index 33cfe1077..f8304a9b3 100644
--- a/python/tox.ini
+++ b/python/tox.ini
@@ -49,7 +49,8 @@ skipsdist = True
 skip_install = True
 deps =
     flake8
-    isort
+# isort 5.11.0 is broken: https://github.com/PyCQA/isort/issues/2031
+    isort<5.11.0
     black
     # pygments required by rst-lint
     pygments