diff --git a/browser/base/content/tabbrowser.xml b/browser/base/content/tabbrowser.xml
index 389fe488a26..300e1ed192d 100644
--- a/browser/base/content/tabbrowser.xml
+++ b/browser/base/content/tabbrowser.xml
@@ -1408,6 +1408,9 @@
 
       <handler event="DOMWindowClose">
         <![CDATA[
+          if (!event.isTrusted)
+            return;
+
           const browsers = this.browsers;
           if (browsers.length == 1)
             return;