diff --git a/BUILD.md b/BUILD.md
index 1f81a50..a0acf7e 100644
--- a/BUILD.md
+++ b/BUILD.md
@@ -1,6 +1,6 @@
 This book is generated using [gitbook](https://github.com/GitbookIO/gitbook).
 
-== How to build the PDF?
+## How to build the PDF?
 
 When gitbook is installed, `gitbook pdf` will generate the PDF of the book.