diff --git a/.readthedocs.yaml b/.readthedocs.yaml
index aa18b42..e241a5e 100644
--- a/.readthedocs.yaml
+++ b/.readthedocs.yaml
@@ -3,6 +3,8 @@ version: 2
 
 build:
   os: 'ubuntu-20.04'
+  tools:
+    python: '3.7'
 
 mkdocs:
   configuration: mkdocs.yml