diff --git a/main.go b/main.go
index fcea445..49657aa 100644
--- a/main.go
+++ b/main.go
@@ -182,7 +182,10 @@ func buildMarkdown(path string, w io.Writer, vars Vars) error {
 	if err != nil {
 		return err
 	}
-	v["content"] = string(blackfriday.Run([]byte(content)))
+	v["content"] = string(blackfriday.Run(
+		[]byte(content),
+		blackfriday.WithExtensions(blackfriday.CommonExtensions|blackfriday.AutoHeadingIDs),
+	))
 	if w == nil {
 		out, err := os.Create(filepath.Join(PUBDIR, renameExt(path, "", ".html")))
 		if err != nil {