diff --git a/docs/book.toml b/docs/book.toml
index 0578cad1f1ae755113b0dc779df2ac3d7ef89234..bd2acfee586f83e2b04fe2414572cadc297861ed 100644
--- a/docs/book.toml
+++ b/docs/book.toml
@@ -8,6 +8,7 @@ site-url = "/docs2/"
 
 [output.html]
 no-section-label = true
+preferred-dark-theme = "light"
 
 [output.html.print]
 enable = false