diff --git a/addons/mail/static/src/components/chat_window_header/chat_window_header.js b/addons/mail/static/src/components/chat_window_header/chat_window_header.js
index eb78f4c4390..428e97048c0 100644
--- a/addons/mail/static/src/components/chat_window_header/chat_window_header.js
+++ b/addons/mail/static/src/components/chat_window_header/chat_window_header.js
@@ -100,6 +100,9 @@ class ChatWindowHeader extends Component {
      */
     _onClickClose(ev) {
         ev.stopPropagation();
+        if (!this.chatWindow) {
+            return;
+        }
         this.chatWindow.close();
     }