diff --git a/.readthedocs.yml b/.readthedocs.yml
index 011e6ad..0d4ef42 100644
--- a/.readthedocs.yml
+++ b/.readthedocs.yml
@@ -1,7 +1,12 @@
 version: 2
 
+build:
+  os: "ubuntu-20.04"
+  tools:
+    python: "3.9"
+    nodejs: "16"
+
 python:
-  version: 3
   install:
     - method: pip
       path: .
diff --git a/docs/conf.py b/docs/conf.py
index fba94f9..94ec1e2 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -191,3 +191,7 @@
 def setup(app):
   app.add_object_type('confval', 'confval',
     'pair: %s; configuration value')
+
+  # Install necessary NPM dependencies
+  import subprocess
+  subprocess.check_output(["npm", "install", "-g", "jsdoc"])
diff --git a/docs/requirements.txt b/docs/requirements.txt
index 96a38ea..fc516d5 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -1,6 +1,7 @@
 sphinx==3.5.1
+docutils==0.16.0
 sphinx-prompt==1.1.0
 sphinx-tabs==2.0.1
-sphinx-rtd-theme==0.4.3
+sphinx-rtd-theme==1.0.0
 sphinx-notfound-page==0.3
 sphinx-js==3.1
diff --git a/tox.ini b/tox.ini
index fe36096..a0ce1ec 100644
--- a/tox.ini
+++ b/tox.ini
@@ -13,6 +13,7 @@ deps =
   sphinx1: Sphinx<2.0
   sphinx2: Sphinx<3.0
   sphinx3: Sphinx<4.0
+  {sphinx1,sphinx2,sphinx3}: docutils<0.18
   sphinxlatest: Sphinx
 commands = pytest {posargs}