diff --git a/lib/_stream_writable.js b/lib/_stream_writable.js
index 78ab13d9063c67..334f492ba68eef 100644
--- a/lib/_stream_writable.js
+++ b/lib/_stream_writable.js
@@ -248,7 +248,7 @@ function validChunk(stream, state, chunk, cb) {
 Writable.prototype.write = function(chunk, encoding, cb) {
   var state = this._writableState;
   var ret = false;
-  var isBuf = Stream._isUint8Array(chunk) && !state.objectMode;
+  var isBuf = !state.objectMode && Stream._isUint8Array(chunk);
 
   if (isBuf && Object.getPrototypeOf(chunk) !== Buffer.prototype) {
     chunk = Stream._uint8ArrayToBuffer(chunk);