diff --git a/lib/browser/api/dialog.js b/lib/browser/api/dialog.js
index 24285704843af..5d5b96979874c 100644
--- a/lib/browser/api/dialog.js
+++ b/lib/browser/api/dialog.js
@@ -249,7 +249,11 @@ module.exports = {
   },
 
   showCertificateTrustDialog: function (window, options) {
-    if (window && window.constructor !== BrowserWindow) options = window;
+    if (window && window.constructor !== BrowserWindow) {
+      options = window;
+      window = null;
+    }
+
     if (options == null || typeof options !== 'object') {
       throw new TypeError('options must be an object');
     }