diff --git a/externs/webcomponents-externs.js b/externs/webcomponents-externs.js
index 121b5d1925..f7bba2421f 100644
--- a/externs/webcomponents-externs.js
+++ b/externs/webcomponents-externs.js
@@ -12,24 +12,6 @@ let HTMLImports = {
 
 window.HTMLImports = HTMLImports;
 
-let ShadyCSS = {
-  /**
-   * @param {!HTMLElement} element
-   * @param {Object=} overrides
-   */
-  applyStyle(element, overrides){},
-  updateStyles(){},
-  /**
-   * @param {!HTMLTemplateElement} template
-   * @param {string} is
-   * @param {string=} extendsElement
-   */
-  prepareTemplate(template, is, extendsElement){},
-  nativeCss: false,
-  nativeShadow: false
-};
-window.ShadyCSS = ShadyCSS;
-
 let ShadyDOM = {
   inUse: false,
   flush(){},
diff --git a/gulpfile.js b/gulpfile.js
index 25d15c02d6..65a5c3111b 100644
--- a/gulpfile.js
+++ b/gulpfile.js
@@ -87,7 +87,7 @@ class Log extends Transform {
 }
 
 let CLOSURE_LINT_ONLY = false;
-let EXPECTED_WARNING_COUNT = 503;
+let EXPECTED_WARNING_COUNT = 498;
 
 gulp.task('closure', ['clean'], () => {
 
@@ -142,6 +142,7 @@ gulp.task('closure', ['clean'], () => {
     new_type_inf: true,
     checks_only: CLOSURE_LINT_ONLY,
     externs: [
+      'bower_components/shadycss/externs/shadycss-externs.js',
       'externs/webcomponents-externs.js',
       'externs/polymer-externs.js',
       'externs/closure-types.js',