diff --git a/lib/combo.js b/lib/combo.js
index f4779d1..d0dabfd 100644
--- a/lib/combo.js
+++ b/lib/combo.js
@@ -46,8 +46,8 @@ module.exports = function (options, PROD) {
 				cached = {};
 			}
 			if (PROD) {
-				res.setHeader('Expires', 'Mon, 1 Jan 2100 00:00:00 GMT')
-				res.setHeader('Last-Modified', 'Mon, 1 Jan 2100 00:00:00 GMT')
+				res.setHeader('Expires', 'Fri, 1 Jan 2100 00:00:00 GMT')
+				res.setHeader('Last-Modified', 'Fri, 1 Jan 2100 00:00:00 GMT')
 				res.setHeader('Cache-Control', 'public, max-age=' + 60 * 60 * 24 * 365);
 				res.setHeader('Pragma', 'public');
 			}
@@ -87,4 +87,4 @@ module.exports = function (options, PROD) {
 			}
 		}
 	};
-};
\ No newline at end of file
+};