diff --git a/netlify.toml b/netlify.toml
index c56ebaf1ff4..060fe928ef3 100644
--- a/netlify.toml
+++ b/netlify.toml
@@ -1,6 +1,7 @@
 [build]
 base = "book/"
 command = "make deps && make pathways"
+environment = { PYTHON_VERSION = "3.10" }
 publish = "website/_build/html"
 
 # Do not build deploy previews for branches from all-contributors bot