diff --git a/lib/Page.js b/lib/Page.js
index 46019550..0807dd0b 100644
--- a/lib/Page.js
+++ b/lib/Page.js
@@ -295,6 +295,7 @@ class Page extends EventEmitter {
 
   /**
    * @param {Object} options
+   * @return {!Promise<!Puppeteer.ElementHandle>}
    */
   async addScriptTag(options) {
     return this.mainFrame().addScriptTag(options);
@@ -302,6 +303,7 @@ class Page extends EventEmitter {
 
   /**
    * @param {Object} options
+   * @return {!Promise<!Puppeteer.ElementHandle>}
    */
   async addStyleTag(options) {
     return this.mainFrame().addStyleTag(options);