--- a/browser/base/content/tabbrowser.xml
+++ b/browser/base/content/tabbrowser.xml
@@ -3096,16 +3096,17 @@
                  class="tab-icon-image"
                  role="presentation"/>
       <xul:label flex="1"
                  xbl:inherits="value=label,crop,accesskey"
                  class="tab-text"
                  role="presentation"/>
       <xul:toolbarbutton anonid="close-button"
                          tabindex="-1"
+                         clickthrough="never"
                          class="tab-close-button"/>
     </content>
 
     <implementation>
       <property name="pinned" readonly="true">
         <getter>
           return this.getAttribute("pinned") == "true";
         </getter>