diff --git a/README.md b/README.md
index 43b1de2..094e58a 100644
--- a/README.md
+++ b/README.md
@@ -15,6 +15,8 @@ Register the bundle in AppKernel.php:
 new Mapbender\LDAPBundle\MapbenderLDAPBundle(),
 ```
 
+Enable LDAP extension for php.
+
 ### 2. Configuration
 
 In the `security.yml` add the ldapProvider and some firewall configuration: