diff --git a/.readthedocs.yaml b/.readthedocs.yaml
index 022adb1..d588382 100644
--- a/.readthedocs.yaml
+++ b/.readthedocs.yaml
@@ -10,6 +10,7 @@ build:
   jobs:
     post_install:
       - pip install -e .
+      - pip install sphinx-rtd-theme
 
 # Build documentation in the "docs/" directory with Sphinx
 sphinx: