diff --git a/tox.ini b/tox.ini
index ebf44d3..3396bf9 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,6 +1,6 @@
 # to run for a specific environment, use ``tox -e ENVNAME``
 [tox]
-envlist = py27,py36,py37,py38,py39,py310,pypy3
+envlist = py27,py36,py37,py38,py39,py310,pypy3,docs
 
 [testenv]
 deps =
@@ -19,5 +19,6 @@ commands =
 deps =
     -r {toxinidir}/requirements_docs.txt
 changedir = docs
+allowlist_externals = make
 commands =
     make html