diff --git a/admin_manual/installation/source_installation.rst b/admin_manual/installation/source_installation.rst
index 6e061e12f..a44b7adab 100644
--- a/admin_manual/installation/source_installation.rst
+++ b/admin_manual/installation/source_installation.rst
@@ -60,6 +60,7 @@ Required:
 * PHP module XMLWriter
 * PHP module zip
 * PHP module zlib
+* PHP module sodium (for password hashing)
 
 Database connectors (pick the one for your database:)