diff --git a/build.sh b/build.sh
index 1565c9a..a0569ca 100755
--- a/build.sh
+++ b/build.sh
@@ -11,6 +11,7 @@ pandoc \
 --verbose \
 --standalone \
 --self-contained \
+--number-sections \
 --output "${OUTPUT}/index.html" \
 --write 'revealjs' \
 -V revealjs-url='/sw/revealjs/up' \