diff --git a/src/index.js b/src/index.js
index 890b783..0bc9000 100644
--- a/src/index.js
+++ b/src/index.js
@@ -12,7 +12,7 @@
 /* eslint-env browser */
 const KNOWN_PROPERTIES = ['weight', 'id', 'referer', 'checkpoint', 't', 'source', 'target', 'cwv', 'CLS', 'FID', 'LCP', 'INP', 'TTFB'];
 const DEFAULT_TRACKING_EVENTS = ['click', 'cwv', 'form', 'enterleave', 'viewblock', 'viewmedia', 'loadresource', 'utm'];
-const { sampleRUM, queue, isSelected } = window.hlx ? window.hlx.rum : {};
+const { sampleRUM, queue, isSelected } = window.hlx && window.hlx.rum ? window.hlx.rum : {};
 
 const urlSanitizers = {
   full: () => window.location.href,