diff --git a/browser/base/content/tabbrowser.xml b/browser/base/content/tabbrowser.xml
index 3d04ec1e4592..c40893ae0004 100644
--- a/browser/base/content/tabbrowser.xml
+++ b/browser/base/content/tabbrowser.xml
@@ -2299,6 +2299,9 @@
           if (!event.isTrusted)
             return;
 
+          if (this.mTabs.length == 1)
+            return;
+
           var tab = this._getTabForContentWindow(event.target);
           if (tab) {
             this.removeTab(tab);