diff --git a/src/node/utils/caching_middleware.js b/src/node/utils/caching_middleware.js
index a31fc1bcc..366085c4b 100644
--- a/src/node/utils/caching_middleware.js
+++ b/src/node/utils/caching_middleware.js
@@ -196,7 +196,7 @@ CachingMiddleware.prototype = new function () {
         var statusCode = responseCache[cacheKey].statusCode;
 
         var pathStr = CACHE_DIR + 'minified_' + cacheKey;
-        if (supportsGzip && (headers['content-type'] || '').match(/^application\/javascript/)) {
+        if (supportsGzip && /^application\/javascript/.test(headers['content-type'])) {
           pathStr = pathStr + '.gz';
           headers['content-encoding'] = 'gzip';
         } else {