diff --git a/lib/_stream_readable.js b/lib/_stream_readable.js
index 35b360b88b90f2..9438bf92d34ee2 100644
--- a/lib/_stream_readable.js
+++ b/lib/_stream_readable.js
@@ -467,7 +467,7 @@ function maybeReadMore_(stream, state) {
 // for virtual (non-string, non-buffer) streams, "length" is somewhat
 // arbitrary, and perhaps not very meaningful.
 Readable.prototype._read = function(n) {
-  this.emit('error', new Error('not implemented'));
+  this.emit('error', new Error('_read() is not implemented'));
 };
 
 Readable.prototype.pipe = function(dest, pipeOpts) {
diff --git a/lib/_stream_transform.js b/lib/_stream_transform.js
index 89797a2210055b..892c80459a3649 100644
--- a/lib/_stream_transform.js
+++ b/lib/_stream_transform.js
@@ -139,7 +139,7 @@ Transform.prototype.push = function(chunk, encoding) {
 // an error, then that'll put the hurt on the whole operation.  If you
 // never call cb(), then you'll never get another chunk.
 Transform.prototype._transform = function(chunk, encoding, cb) {
-  throw new Error('Not implemented');
+  throw new Error('_transform() is not implemented');
 };
 
 Transform.prototype._write = function(chunk, encoding, cb) {
diff --git a/lib/_stream_writable.js b/lib/_stream_writable.js
index c0264df04b4872..9e462a8f60e3e3 100644
--- a/lib/_stream_writable.js
+++ b/lib/_stream_writable.js
@@ -453,7 +453,7 @@ function clearBuffer(stream, state) {
 }
 
 Writable.prototype._write = function(chunk, encoding, cb) {
-  cb(new Error('_write() method is not implemented'));
+  cb(new Error('_write() is not implemented'));
 };
 
 Writable.prototype._writev = null;