--- a/mobile/chrome/content/sync.js
+++ b/mobile/chrome/content/sync.js
@@ -47,16 +47,19 @@ let WeaveGlue = {
     Weave.Service.keyGenEnabled = false;
   },
 
   openRemoteTabs: function openRemoteTabs() {
     BrowserUI.newOrSelectTab("about:sync-tabs", null);
   },
 
   connect: function connect() {
+    if (this._settings.user.value != Weave.Service.username)
+      Weave.Service.startOver();
+
     Weave.Service.login(this._settings.user.value, this._settings.pass.value,
       this._settings.secret.value);
     Weave.Service.persistLogin();
   },
 
   disconnect: function disconnect() {
     Weave.Service.logout();
   },