diff --git a/doc/api/buffers.markdown b/doc/api/buffers.markdown
index 37e7ffc72c5..2a9b973af64 100644
--- a/doc/api/buffers.markdown
+++ b/doc/api/buffers.markdown
@@ -113,7 +113,7 @@ buffer object.  It does not change when the contents of the buffer are changed.
     // 1234
     // 1234
 
-### buffer.copy(targetBuffer, targetStart, sourceStart=0, sourceEnd=buffer.length)
+### buffer.copy(targetBuffer, targetStart=0, sourceStart=0, sourceEnd=buffer.length)
 
 Does a memcpy() between buffers.
 
diff --git a/lib/buffer.js b/lib/buffer.js
index 7418aad458f..ab51ddfb720 100644
--- a/lib/buffer.js
+++ b/lib/buffer.js
@@ -280,11 +280,12 @@ Buffer.prototype.toString = function (encoding, start, end) {
 Buffer.byteLength = SlowBuffer.byteLength;
 
 
-// copy(targetBuffer, targetStart, sourceStart=0, sourceEnd=buffer.length)
+// copy(targetBuffer, targetStart=0, sourceStart=0, sourceEnd=buffer.length)
 Buffer.prototype.copy = function copy (target, target_start, start, end) {
   var source = this;
   start || (start = 0);
   end   || (end   = this.length);
+  target_start || (target_start = 0);
 
   if (end < start) throw new Error("sourceEnd < sourceStart");