diff --git a/src/transaction.js b/src/transaction.js
index e9590d8..d2d7a16 100644
--- a/src/transaction.js
+++ b/src/transaction.js
@@ -133,7 +133,6 @@ Transaction.prototype.toBuffer = function () {
 
   var offset = 0
   function writeSlice(slice) {
-    if (Array.isArray(slice)) slice = new Buffer(slice) // FIXME: Performance: transitionary only
     slice.copy(buffer, offset)
     offset += slice.length
   }