diff --git a/tox.ini b/tox.ini
index 6585e57..d5629f0 100644
--- a/tox.ini
+++ b/tox.ini
@@ -26,6 +26,7 @@ deps = -r{toxinidir}/doc/requirements.txt
 allowlist_externals =
   mkdir
   cp
+  find
 commands =
   {[testenv:api-ref]commands}
   {[testenv:json-api-ref]commands}