diff --git a/INSTALL.md b/INSTALL.md
index 9bc7705..0b2de4e 100644
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -19,7 +19,7 @@ options](#configuration) to adjust as you see fit.
     - com_dotnet extension
 - GD extension
 - zlib extension
-- some disk space or (optionally) an SQL database
+- some disk space or (optionally) a database supported by [PDO](https://php.net/manual/book.pdo.php)
 - ability to create files and folders in the installation directory and the PATH defined in index.php
 - A web browser with JavaScript support