diff --git a/lib/appenders/hipchat.js b/lib/appenders/hipchat.js
index f72f812..6f47f81 100644
--- a/lib/appenders/hipchat.js
+++ b/lib/appenders/hipchat.js
@@ -26,7 +26,7 @@ function hipchatAppender(_config, _layout) {
         var data = {
             room_id: _config.room_id,
             from: _config.from,
-            message: layout(loggingEvent, config.timezoneOffset),
+            message: layout(loggingEvent, _config.timezoneOffset),
             format: _config.format,
             color: colours[loggingEvent.level.toString()],
             notify: _config.notify