diff --git a/book/book.toml b/book/book.toml
index cc8de95c..157f2b8d 100644
--- a/book/book.toml
+++ b/book/book.toml
@@ -1,7 +1,6 @@
 [book]
 authors = ["Kevin R. Thornton"]
 language = "en"
-multilingual = false
 src = "src"
 title = "The tskit (rust) book"