diff --git a/.readthedocs.yml b/.readthedocs.yml
index 65f39b7ff82e12eb11c0f855e5ed9ef94fd5f5a7..d89fbf96f0796e6234c1d360a6dbecdfe86bbbc5 100644
--- a/.readthedocs.yml
+++ b/.readthedocs.yml
@@ -20,6 +20,10 @@ build:
   os: ubuntu-20.04
   tools:
     python: "3.10"
+  apt_packages:
+    - graphviz
+    - plantuml
+    - pandoc
 
 python:
   install:
diff --git a/doc/doc_requirements.txt b/doc/doc_requirements.txt
index 88ad7b4474ee07b44cf8e5e16197755c548078fc..211b0ca1b9096dc774e51b65ef8c8c1954e1d2b7 100644
--- a/doc/doc_requirements.txt
+++ b/doc/doc_requirements.txt
@@ -1,5 +1,5 @@
 
-sphinx==3.5.1
+sphinx==6.1.3
 
 # A streamlined version of devmode_requirements.txt for doc building
 -e ./tools/exekall
diff --git a/setup.py b/setup.py
index 222f27a8cfd3141ba3e2e40c3a0d29ad5ee29997..0f6b8b8eb86fc19a4f5b3e34f20d1e2b2427c733 100755
--- a/setup.py
+++ b/setup.py
@@ -77,9 +77,9 @@ extras_require={
 }
 
 extras_require["doc"] = [
-    "sphinx >= 1.8",
     # Force ReadTheDocs to use a recent version, rather than the defaults used
     # for old projects.
+    "sphinx > 2",
     "sphinx_rtd_theme >= 0.5.2",
     "sphinxcontrib-plantuml",
     "nbsphinx",