diff --git a/swupdate b/swupdate
new file mode 100755
index 0000000..4437508
--- /dev/null
+++ b/swupdate
@@ -0,0 +1,5 @@
+#!/usr/bin/env bash
+set -eo pipefail
+
+var="const currentVersion = '$RANDOM';"
+sed -i "1s/.*/$var/" sw.js