diff --git a/lib/logger.js b/lib/logger.js
index b862a7d..bb05fec 100644
--- a/lib/logger.js
+++ b/lib/logger.js
@@ -61,7 +61,7 @@ function RequestLogger(logger, level) {
   return expressWinston.logger({
     winstonInstance: logger,
     expressFormat: false,
-    msg: "{{req.method}} {{req.url}} {{res.statusCode}} {{res.responseTime}}ms",
+    msg: '{{req.method}} {{req.url}} {{res.statusCode}} {{res.responseTime}}ms',
     level: logLevel,
     baseMeta: {sourceName: 'request'}
   });