diff --git a/src/modules/app_ruby/doc/app_ruby_admin.xml b/src/modules/app_ruby/doc/app_ruby_admin.xml
index d69d4d880a6..872c6cf0d65 100644
--- a/src/modules/app_ruby/doc/app_ruby_admin.xml
+++ b/src/modules/app_ruby/doc/app_ruby_admin.xml
@@ -85,7 +85,37 @@ modparam("app_ruby", "load", "/usr/local/etc/kamailio/ruby/myscript.rb")
-
+
+ xval_mode (int)
+
+ Control if the external sub-module functions returning extended-values
+ should propagate their string return value (when set to 0) or be
+ replaced by NULL/nil (when set to 1).
+
+
+ When set to 0, the KSR::PV Ruby submodule is implemented with the
+ internal functions from the app_ruby module, otherwise the ones from
+ core are used.
+
+
+ Note: when set to 1, there were crashing reports that are under
+ investigation, this option being provided as intermediary
+ solution to preserve the behaviour from older versions.
+
+
+
+ Default value is 0
.
+
+
+
+ Set xval_mode parameter
+
+...
+modparam("app_ruby", "xval_mode", 1)
+...
+
+
+