diff --git a/src/plugins/sib-reply-to-message.js b/src/plugins/sib-reply-to-message.js
index 2b7e8d05f8c4f97a33719092a513770b245386b2..1d878ce48bed645dd3807d97246ab2e4ce2a9a4d 100644
--- a/src/plugins/sib-reply-to-message.js
+++ b/src/plugins/sib-reply-to-message.js
@@ -14,9 +14,8 @@ converse.plugins.add('sib-reply-to-message', {
 
     api.listen.on('getMessageActionButtons', (el, buttons) => {
 
-      // Do not add if the message is not from a MUC
       // Do not add if the message is from the current user
-      if (el.model.get('type') !== 'groupchat' || el.model.get('sender') === 'me') {
+      if (el.model.get('sender') === 'me') {
         return buttons;
       }
 
@@ -32,8 +31,12 @@ converse.plugins.add('sib-reply-to-message', {
             chat_textarea.value += `${message.replace(/^/gm, '>')}\n`;
           }
 
-          // Add mention to the initial user and focus textarea
-          chat_textarea.value += `@${el.model.get('nick')} `;
+          // Add mention to the initial author for MUCs
+          const nickname = el.model.get('nick');
+          if (el.model.get('type') === 'groupchat' && nickname.length) {
+            chat_textarea.value += `@${nickname} `;
+          }
+
           chat_textarea.focus();
         },
         'button_class': 'chat-msg__action-reply',