diff --git a/src/node/hooks/express/static.js b/src/node/hooks/express/static.js
index e8f9afbb8..9209967ce 100644
--- a/src/node/hooks/express/static.js
+++ b/src/node/hooks/express/static.js
@@ -35,7 +35,7 @@ exports.expressCreateServer = function (hook_name, args, cb) {
   // serve plugin definitions
   // not very static, but served here so that client can do require("pluginfw/static/js/plugin-definitions.js");
   args.app.get('/pluginfw/plugin-definitions.json', function (req, res, next) {
-    res.header("Content-Type","application/json; charset: utf-8");
+    res.header("Content-Type","application/json; charset=utf-8");
     res.write(JSON.stringify({"plugins": plugins.plugins, "parts": plugins.parts}));
     res.end();
   });