--- a/devtools/client/netmonitor/components/filter-buttons.js
+++ b/devtools/client/netmonitor/components/filter-buttons.js
@@ -19,16 +19,17 @@ function FilterButtons({
     checked && classList.push("checked");
 
     return button({
       id: `requests-menu-filter-${type}-button`,
       className: classList.join(" "),
       "data-key": type,
       onClick: triggerFilterType,
       onKeyDown: triggerFilterType,
+      "aria-pressed": checked,
     }, L10N.getStr(`netmonitor.toolbar.filter.${type}`));
   }).toArray();
 
   return div({ id: "requests-menu-filter-buttons" }, buttons);
 }
 
 FilterButtons.PropTypes = {
   state: PropTypes.object.isRequired,