diff --git a/build.sh b/build.sh
index 6bb72f7..80fe371 100755
--- a/build.sh
+++ b/build.sh
@@ -16,7 +16,7 @@ pandoc \
 --output "${OUTPUT}/index.html" \
 \
 --number-sections \
---slide-level '2' \
+--slide-level '3' \
 --write 'revealjs' \
 --variable revealjs-url='/sw/revealjs/up' \
 --variable slideNumber \