diff --git a/lib/Page.js b/lib/Page.js
index 4aac20be6f8..6ec9ca6bb1a 100644
--- a/lib/Page.js
+++ b/lib/Page.js
@@ -570,6 +570,11 @@ class Page extends EventEmitter {
     return this.mainFrame().waitFor(selector);
   }
 
+  /**
+   * @param {string} selector
+   * @param {!Array<string>} filePaths
+   * @return {!Promise}
+   */
   async uploadFile(selector, ...filePaths) {
     await this._client.send('DOM.setFileInputFiles', {
       nodeId: await this._querySelector(selector),
diff --git a/phantom_shim/WebPage.js b/phantom_shim/WebPage.js
index 922638a5fac..cd9e3ed1b9c 100644
--- a/phantom_shim/WebPage.js
+++ b/phantom_shim/WebPage.js
@@ -334,7 +334,7 @@ class WebPage {
 
   /**
    * @param {string} selector
-   * @param {string|!Array<string>} files
+   * @param {(string|!Array<string>)} files
    */
   uploadFile(selector, files) {
     if (typeof files === 'string')