diff --git a/addons/mail/static/src/js/chatter.js b/addons/mail/static/src/js/chatter.js
index 635d261bf3f..c0220a7b1b8 100644
--- a/addons/mail/static/src/js/chatter.js
+++ b/addons/mail/static/src/js/chatter.js
@@ -435,7 +435,11 @@ var Chatter = Widget.extend({
      */
      _updateAttachmentCounter: function () {
         var count = this.record.data.message_attachment_count || 0;
-        this.$('.o_chatter_attachment_button_count').html(count);
+        var $element = this.$('.o_chatter_attachment_button_count');
+        if (Number($element.html()) !== count) {
+            this._areAttachmentsLoaded = false;
+            $element.html(count);
+        }
      },
     /**
      * @private