diff --git a/lib/appenders/gelf.js b/lib/appenders/gelf.js
index 8e075b5..e536462 100644
--- a/lib/appenders/gelf.js
+++ b/lib/appenders/gelf.js
@@ -48,7 +48,9 @@ function gelfAppender (layout, host, port, hostname, facility) {
   host = host || 'localhost';
   port = port || 12201;
   hostname = hostname || require('os').hostname();
-  facility = facility || 'nodejs-server';
+  if(facility) {
+    customFields['_facility'] = facility;
+  }
   layout = layout || layouts.messagePassThroughLayout;
 
   var defaultCustomFields = customFields || {};
@@ -103,7 +105,6 @@ function gelfAppender (layout, host, port, hostname, facility) {
     msg.timestamp = msg.timestamp || new Date().getTime() / 1000; // log should use millisecond 
     msg.host = hostname;
     msg.level = levelMapping[loggingEvent.level || levels.DEBUG];
-    msg.facility = facility;
     return msg;
   }