diff --git a/lib/mixins/element-mixin.js b/lib/mixins/element-mixin.js
index 9dbc0fd965..fb5ee7ec01 100644
--- a/lib/mixins/element-mixin.js
+++ b/lib/mixins/element-mixin.js
@@ -24,7 +24,7 @@ import { wrap } from '../utils/wrap.js';
  * Current Polymer version in Semver notation.
  * @type {string} Semver notation of the current version of Polymer.
  */
-export const version = '3.3.1';
+export const version = '3.4.0';
 
 export const builtCSS = window.ShadyCSS && window.ShadyCSS['cssBuild'];