diff --git a/addons/mail/static/src/models/discuss.js b/addons/mail/static/src/models/discuss.js
index c44eee4de82..3ff68d89164 100644
--- a/addons/mail/static/src/models/discuss.js
+++ b/addons/mail/static/src/models/discuss.js
@@ -34,6 +34,9 @@ registerModel({
          * @param {integer} ui.item.id
          */
         async handleAddChannelAutocompleteSelect(ev, ui) {
+            // Necessary in order to prevent AutocompleteSelect event's default
+            // behaviour as html tags visible for a split second in text area
+            ev.preventDefault();
             const name = this.addingChannelValue;
             this.clearIsAddingItem();
             if (ui.item.special) {