diff --git a/book.toml b/book.toml
index 5dd755684..e5f4ee7c4 100644
--- a/book.toml
+++ b/book.toml
@@ -5,4 +5,4 @@ author = "The Rust Project Developers"
 
 [output.html]
 
-additional-css = ["src/theme/reference.css"]
+additional-css = ["theme/reference.css"]
diff --git a/src/theme/header.hbs b/theme/header.hbs
similarity index 100%
rename from src/theme/header.hbs
rename to theme/header.hbs
diff --git a/src/theme/reference.css b/theme/reference.css
similarity index 100%
rename from src/theme/reference.css
rename to theme/reference.css