diff --git a/lib/logging.js b/lib/logging.js
index 5b13b397e7207cd7b28a5cc03437c56d6c34a0a7..d868df2f772c92da03767466d3abd83d5818029a 100644
--- a/lib/logging.js
+++ b/lib/logging.js
@@ -37,7 +37,7 @@ var filename = path.join(log_path, configuration.get('process_type') + ".log");
 
 exports.logger = new (winston.Logger)({
   transports: [new (winston.transports.File)({
-    timestamp: true,
+    timestamp: function () { return new Date().toISOString() },
     filename: filename,
     colorize: true,
     handleExceptions: !!process.env['LOG_TO_CONSOLE']