diff --git a/build-21.sh b/build-21.sh
new file mode 100755
index 0000000000..2e653a71ae
--- /dev/null
+++ b/build-21.sh
@@ -0,0 +1,10 @@
+#! /bin/sh
+
+# Download main branch
+curl -Lo wcag.tar.gz https://github.com/w3c/wcag/archive/refs/heads/main.tar.gz
+tar xf wcag.tar.gz
+cd wcag-main
+npm i
+
+# Run build using local 2.1 guidelines from active branch
+WCAG_VERSION=21 WCAG_FORCE_LOCAL_GUIDELINES=../guidelines/index.html npm run build