diff --git a/light9/web/lib/parse-prometheus-text-format.d.ts b/light9/web/lib/parse-prometheus-text-format.d.ts
new file mode 100644
--- /dev/null
+++ b/light9/web/lib/parse-prometheus-text-format.d.ts
@@ -0,0 +1,4 @@
+declare module "parse-prometheus-text-format" {
+  function parsePrometheusTextFormat(s: string): any;
+  export default parsePrometheusTextFormat;
+}