--- a/services/fxaccounts/FxAccountsWebChannel.jsm
+++ b/services/fxaccounts/FxAccountsWebChannel.jsm
@@ -505,18 +505,17 @@ this.FxAccountsWebChannelHelpers.prototy
     let body = sb.GetStringFromName("relinkVerify.heading") +
                "\n\n" + description;
     let ps = Services.prompt;
     let buttonFlags = (ps.BUTTON_POS_0 * ps.BUTTON_TITLE_IS_STRING) +
                       (ps.BUTTON_POS_1 * ps.BUTTON_TITLE_CANCEL) +
                       ps.BUTTON_POS_1_DEFAULT;
 
     // If running in context of the browser chrome, window does not exist.
-    var targetWindow = typeof window === "undefined" ? null : window;
-    let pressed = Services.prompt.confirmEx(targetWindow, title, body, buttonFlags,
+    let pressed = Services.prompt.confirmEx(null, title, body, buttonFlags,
                                        continueLabel, null, null, null,
                                        {});
     return pressed === 0; // 0 is the "continue" button
   }
 };
 
 var singleton;
 // The entry-point for this module, which ensures only one of our channels is