diff --git a/src/contentScripts/communityConsole/utils/common.js b/src/contentScripts/communityConsole/utils/common.js
index ac4db4e..2e33f99 100644
--- a/src/contentScripts/communityConsole/utils/common.js
+++ b/src/contentScripts/communityConsole/utils/common.js
@@ -61,6 +61,17 @@
   return clone;
 }
 
+// Returns true if |node| is the "mark as read/unread" button, the parent of the
+// parent of |node| is the actions bar of the thread list, and the button with
+// debugid |debugid| is NOT part of the actions bar.
+export function shouldAddBtnToActionBar(debugid, node) {
+  return node?.tagName == 'MATERIAL-BUTTON' &&
+      (node.getAttribute?.('debugid') == 'mark-read-button' ||
+       node.getAttribute?.('debugid') == 'mark-unread-button') &&
+      node.parentNode?.querySelector('[debugid="' + debugid + '"]') === null &&
+      node.parentNode?.parentNode?.tagName == 'EC-BULK-ACTIONS';
+}
+
 // Returns the display language set by the user.
 export function getDisplayLanguage() {
   var startup =