diff --git a/.readthedocs.yaml b/.readthedocs.yaml
index 51911a7..ed3daf6 100644
--- a/.readthedocs.yaml
+++ b/.readthedocs.yaml
@@ -4,6 +4,9 @@ build:
   os: ubuntu-20.04
   tools:
     python: "3.9"
+  jobs:
+    pre_install:
+      - apt install cmake
 
 sphinx:
   builder: html