diff --git a/app/javascript/dashboard/helper/conversationHelper.js b/app/javascript/dashboard/helper/conversationHelper.js
index 3f40a98fb..66194e003 100644
--- a/app/javascript/dashboard/helper/conversationHelper.js
+++ b/app/javascript/dashboard/helper/conversationHelper.js
@@ -47,12 +47,13 @@ export const filterDuplicateSourceMessages = (messages = []) => {
  * @returns {Object} The last message of the conversation.
  */
 export const getLastMessage = m => {
-  const lastMessageIncludingActivity = m.messages.at(-1);
+  const lastMessageIncludingActivity = m.messages[m.messages.length - 1];
 
   const nonActivityMessages = m.messages.filter(
     message => message.message_type !== 2
   );
-  const lastNonActivityMessageInStore = nonActivityMessages.at(-1);
+  const lastNonActivityMessageInStore =
+    nonActivityMessages[nonActivityMessages.length - 1];
 
   const lastNonActivityMessageFromAPI = m.last_non_activity_message;