diff --git a/resources/install/scripts/app/xml_handler/resources/scripts/directory/directory.lua b/resources/install/scripts/app/xml_handler/resources/scripts/directory/directory.lua
index b078f273e5..f0ccecce4e 100644
--- a/resources/install/scripts/app/xml_handler/resources/scripts/directory/directory.lua
+++ b/resources/install/scripts/app/xml_handler/resources/scripts/directory/directory.lua
@@ -256,8 +256,8 @@
 								else
 									--set a default dial string
 										if (dial_string == null) then
-											local ext = (#number_alias > 0) and number_alias or extension
-											dial_string = "{sip_invite_domain=" .. domain_name .. ",presence_id=" .. user .. "@" .. domain_name .. "}${sofia_contact(" .. ext .. "@" .. domain_name .. ")}";
+											local username = (#number_alias > 0) and number_alias or extension
+											dial_string = "{sip_invite_domain=" .. domain_name .. ",presence_id=" .. user .. "@" .. domain_name .. "}${sofia_contact(" .. username .. "@" .. domain_name .. ")}";
 										end
 									--set the an alternative dial string if the hostnames don't match
 										if (load_balancing) then