diff --git a/package.json b/package.json
index 0a6b2a2..e0dbb42 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "colyseus.js",
-  "version": "0.15.15-preview.21",
+  "version": "0.15.15-preview.22",
   "description": "Colyseus Multiplayer SDK for JavaScript/TypeScript",
   "author": "Endel Dreyer",
   "license": "MIT",
diff --git a/src/Auth.ts b/src/Auth.ts
index a178910..2c20df0 100644
--- a/src/Auth.ts
+++ b/src/Auth.ts
@@ -114,9 +114,12 @@ export class Auth {
             const w = settings.width || 480;
             const h = settings.height || 768;
 
+            // forward existing token for upgrading
+            const upgradingToken = this.token ? `?token=${this.token}` : "";
+
             // Capitalize first letter of providerName
             const title = `Login with ${(providerName[0].toUpperCase() + providerName.substring(1))}`;
-            const url = this.http['client']['getHttpEndpoint'](`${(settings.prefix || `${this.settings.path}/provider`)}/${providerName}`);
+            const url = this.http['client']['getHttpEndpoint'](`${(settings.prefix || `${this.settings.path}/provider`)}/${providerName}${upgradingToken}`);
 
             const left = (screen.width / 2) - (w / 2);
             const top = (screen.height / 2) - (h / 2);