diff --git a/serve-static/serve-static-tests.ts b/serve-static/serve-static-tests.ts
index 6b16e842b2..36d2761cdd 100644
--- a/serve-static/serve-static-tests.ts
+++ b/serve-static/serve-static-tests.ts
@@ -18,3 +18,9 @@ app.use(serveStatic('/3', {
         res.setHeader('Server', 'server-static middleware');
     }
 }));
+
+serveStatic.mime.define({
+    'application/babylon': ['babylon'],
+    'application/babylonmeshdata': ['babylonmeshdata'],
+    'application/fx': ['fx']
+});
\ No newline at end of file
diff --git a/serve-static/serve-static.d.ts b/serve-static/serve-static.d.ts
index b116d43848..f7d7e502f1 100644
--- a/serve-static/serve-static.d.ts
+++ b/serve-static/serve-static.d.ts
@@ -11,6 +11,7 @@
  =============================================== */
 
 /// <reference path="../express/express.d.ts" />
+/// <reference path="../mime/mime.d.ts" />
 
 declare module "serve-static" {
     import express = require('express');
@@ -75,5 +76,11 @@ declare module "serve-static" {
         setHeaders?: (res: express.Response, path: string, stat: any) => any;
     }): express.Handler;
 
+    import m = require('mime');
+
+    module serveStatic {
+        var mime: typeof m;
+    }
+
     export = serveStatic;
 }