diff --git a/book.toml b/book.toml
index 6cca7f62e5ee8..5dd7556845a41 100644
--- a/book.toml
+++ b/book.toml
@@ -5,4 +5,4 @@ author = "The Rust Project Developers"
 
 [output.html]
 
-additional-css = ["theme/reference.css"]
\ No newline at end of file
+additional-css = ["src/theme/reference.css"]
diff --git a/theme/header.hbs b/src/theme/header.hbs
similarity index 100%
rename from theme/header.hbs
rename to src/theme/header.hbs
diff --git a/theme/reference.css b/src/theme/reference.css
similarity index 100%
rename from theme/reference.css
rename to src/theme/reference.css