diff --git a/.readthedocs.yaml b/.readthedocs.yaml
index 061090c2..2ed53743 100644
--- a/.readthedocs.yaml
+++ b/.readthedocs.yaml
@@ -10,6 +10,11 @@ build:
   os: ubuntu-22.04
   tools:
     python: "mambaforge-22.9"
+  jobs:
+    # Read the docs needs a couple packages not in the environment file
+    pre_install:
+      - conda install -y cmake compilers sphinx sphinxcontrib-bibtex
+      - conda install sphinx_rtd_theme>=1.3
 
 conda:
   environment: environment.yml