diff --git a/lib/make-middleware.js b/lib/make-middleware.js
index b033cbd9..c012fa71 100644
--- a/lib/make-middleware.js
+++ b/lib/make-middleware.js
@@ -30,7 +30,7 @@ function makeMiddleware (setup) {
     var busboy
 
     try {
-      busboy = new Busboy({ headers: req.headers, limits: limits, preservePath: preservePath })
+      busboy = new Busboy({ headers: req.headers, limits: limits, preservePath: preservePath, defParamCharset: 'utf8' })
     } catch (err) {
       return next(err)
     }