--- a/toolkit/components/extensions/parent/ext-identity.js
+++ b/toolkit/components/extensions/parent/ext-identity.js
@@ -9,17 +9,17 @@ Cu.importGlobalProperties(["URL", "XMLHt
 
 var {
   promiseDocumentLoaded,
 } = ExtensionUtils;
 
 const checkRedirected = (url, redirectURI) => {
   return new Promise((resolve, reject) => {
     let xhr = new XMLHttpRequest();
-    xhr.open("HEAD", url);
+    xhr.open("GET", url);
     // We expect this if the user has not authenticated.
     xhr.onload = () => {
       reject(0);
     };
     // An unexpected error happened, log for extension authors.
     xhr.onerror = () => {
       reject(xhr.status);
     };