diff --git a/node_modules/@webcomponents/template/template.js b/node_modules/@webcomponents/template/template.js
index cebfac4..96e03e7 100644
--- a/node_modules/@webcomponents/template/template.js
+++ b/node_modules/@webcomponents/template/template.js
@@ -323,7 +323,7 @@
     var defineOuterHTML = function defineOuterHTML(obj) {
       Object.defineProperty(obj, 'outerHTML', {
         get: function () {
-          return `<${TEMPLATE_TAG}>${this.innerHTML}</${TEMPLATE_TAG}>`;
+          return "<" + TEMPLATE_TAG +">" + this.innerHTML + "</" + TEMPLATE_TAG + ">";
         },
         set: function (innerHTML) {
           if (this.parentNode) {