diff --git a/.zuul.yaml b/.zuul.yaml
index 66a3de1e3f..635ce5ac3f 100644
--- a/.zuul.yaml
+++ b/.zuul.yaml
@@ -278,6 +278,7 @@
     vars:
       node_version: 16
       release_python: python3
+      ensure_tox_version: "<4"
     check:
       jobs:
         - zuul-build-image