diff --git a/lib/forcecharset.js b/lib/forcecharset.js
index c374a7d..1d37d68 100644
--- a/lib/forcecharset.js
+++ b/lib/forcecharset.js
@@ -24,8 +24,9 @@ module.exports = function(req, res, next) {
         if (!buffer) {
             write.call(res, chunk, encoding);
         } else {
-            if (encoding && typeof chunk === 'string') {
-                chunk = new Buffer(chunk, encoding);
+
+            if (typeof chunk === 'string') {
+                chunk = new Buffer(chunk, !!encoding ? encoding : 'utf-8');
             }
             buffer.push(chunk);
             bufferLen += chunk.length;
@@ -38,7 +39,6 @@ module.exports = function(req, res, next) {
         if (chunk) {
             res.write(chunk, encoding);
         }
-
         if (buffer) {
             let buf = Buffer.concat(buffer, bufferLen);
             let out = encodinglib.convert(buf, res.forceCharset);