diff --git a/service/routes/api.js b/service/routes/api.js
index <HASH>..<HASH> 100644
--- a/service/routes/api.js
+++ b/service/routes/api.js
@@ -60,7 +60,7 @@ router.get(/^\/v2\/polyfill(\.\w+)(\.\w+)?/, (req, res) => {
 		features: polyfills.get(),
 		excludes: (typeof req.query.excludes === 'string' && req.query.excludes.split(',')) || [],
 		minify: minified,
-		rum: req.query.rum,
+		rum: (Number.parseInt(req.query.rum, 10) === 1),
 		stream: true
 	};
 	if (req.query.unknown) {
Prevent output of RUM when `rum=0` is included in ?qs (#<I>)