diff --git a/src/js/ga.js b/src/js/ga.js
index b8cf6f9..f498a7e 100644
--- a/src/js/ga.js
+++ b/src/js/ga.js
@@ -7,7 +7,7 @@ if (!dntEnabled()) {
   document.head.appendChild(gaScript);
 
   window.dataLayer = window.dataLayer || [];
-  function gtag() {
+  window.gtag = function() {
     dataLayer.push(arguments);
   }
   gtag("js", new Date());