diff --git a/book.toml b/book.toml
index 6c484e5..f74e96d 100644
--- a/book.toml
+++ b/book.toml
@@ -2,6 +2,7 @@
 title = "Rust 程序设计语言 简体中文版"
 authors = ["Steve Klabnik 和 Carol Nichols，以及来自 Rust 社区的贡献（Rust 中文社区翻译）"]
 description = "Rust 程序设计语言 简体中文版"
+language = "zh-CN"
 
 [output.html]
 additional-css = ["ferris.css", "theme/2018-edition.css"]