diff --git a/lib/server.js b/lib/server.js
index 372c238..6c74c56 100644
--- a/lib/server.js
+++ b/lib/server.js
@@ -47,7 +47,7 @@ class Server {
         res.writeHead(200, {
           'Content-Type': 'image/png',
           'Content-Length': buf.length,
-          'Cache-Control': 'maxage=604800' // Cache hashed favicon for 7 days
+          'Cache-Control': 'max-age=604800' // Cache hashed favicon for 7 days
         }).end(buf)
 
         return