diff --git a/externs/webcomponents-externs.js b/externs/webcomponents-externs.js
index 87b4875f05..c43ef4348a 100644
--- a/externs/webcomponents-externs.js
+++ b/externs/webcomponents-externs.js
@@ -7,7 +7,12 @@ let HTMLImports = {
   /**
    * @param {function()} callback
    */
-  whenReady(callback){}
+  whenReady(callback){},
+  /**
+   * @param {Element} element
+   * @returns {Document} document
+   */
+  importForElement(element){}
 };
 
 window.HTMLImports = HTMLImports;
diff --git a/lib/elements/dom-module.html b/lib/elements/dom-module.html
index 99edb7f109..d808f2b9bf 100644
--- a/lib/elements/dom-module.html
+++ b/lib/elements/dom-module.html
@@ -48,6 +48,7 @@
    * @memberof Polymer
    * @summary Custom element that provides a registry of relocatable DOM content
    *   by `id` that is agnostic to bundling.
+   * @unrestricted
    */
   class DomModule extends HTMLElement {
 
diff --git a/lib/utils/resolve-url.html b/lib/utils/resolve-url.html
index 4b0454eada..357ef6a322 100644
--- a/lib/utils/resolve-url.html
+++ b/lib/utils/resolve-url.html
@@ -23,7 +23,7 @@
      *
      * @memberof Polymer.ResolveUrl
      * @param {string} url Input URL to resolve
-     * @param {string=} baseURI Base URI to resolve the URL against
+     * @param {?string=} baseURI Base URI to resolve the URL against
      * @return {string} resolved URL
      */
     function resolveUrl(url, baseURI) {