diff --git a/admin_manual/configuration_server/config_sample_php_parameters.rst b/admin_manual/configuration_server/config_sample_php_parameters.rst
index f9a79ba4b..b023322e9 100644
--- a/admin_manual/configuration_server/config_sample_php_parameters.rst
+++ b/admin_manual/configuration_server/config_sample_php_parameters.rst
@@ -2047,6 +2047,16 @@ The default cipher for encrypting files. Currently supported are:
 
 Defaults to ``AES-256-CTR``
 
+::
+
+	'encryption.use_legacy_base64_encoding' => false,
+
+Use the legacy base64 format for encrypted files instead of the more space-efficient
+binary format. The option affects only newly written files, existing encrypted files
+will not be touched and will remain readable whether they use the new format or not.
+
+Defaults to ``false``
+
 ::
 
 	'minimum.supported.desktop.version' => '2.0.0',