diff --git a/lib/mixins/element-mixin.js b/lib/mixins/element-mixin.js
index 861d1b120f..7bf6057d3b 100644
--- a/lib/mixins/element-mixin.js
+++ b/lib/mixins/element-mixin.js
@@ -375,7 +375,7 @@ export const ElementMixin = dedupingMixin(base => {
      *     }
      *   }
      *
-     * @return {HTMLTemplateElement|string} Template to be stamped
+     * @return {!HTMLTemplateElement|string} Template to be stamped
      */
     static get template() {
       if (!this.hasOwnProperty(JSCompiler_renameProperty('_template', this))) {
@@ -389,6 +389,15 @@ export const ElementMixin = dedupingMixin(base => {
       return this._template;
     }
 
+    /**
+     * Set the template.
+     *
+     * @param {!HTMLTemplateElement|string} value Template to set.
+     */
+    static set template(value) {
+      this._template = value;
+    }
+
     /**
      * Path matching the url from which the element was imported.
      *