diff --git a/doc/POST_INSTALL.md b/doc/POST_INSTALL.md
index 138bffa..00f1c19 100644
--- a/doc/POST_INSTALL.md
+++ b/doc/POST_INSTALL.md
@@ -1,3 +1,4 @@
 * After installing, you can create your own user using the form
 * Once done, you can (if you want) set the account creation to false in `__INSTALL_DIR__/config.php`
 * If you want to use the app in PWA mode, be sure to be connected to your account first
+* After upgrading from 7.0 to 9.0, you may experience issues if you don't clean your browser cache