diff --git a/README.md b/README.md
index 2287a52..87092b4 100644
--- a/README.md
+++ b/README.md
@@ -23,6 +23,13 @@ A light PHP web interface for managing [mlmmj](http://mlmmj.org/) mailing lists.
 - Audit log of changes
 - Notify admins about errors via Rocket:Chat bot implementation
 
+---
+
+## IMPORTANT
+In case of login issues: Please be aware that the password input field gets sanitized using the filter [FILTER_SANITIZE_FULL_SPECIAL_CHARS](https://www.php.net/manual/en/filter.filters.sanitize.php)
+
+---
+
 ## Installation
 
 Clone the git repository to your webserver: