diff --git a/IPython/nbformat/v3/nbbase.py b/IPython/nbformat/v3/nbbase.py
index f4e312b..c8089d7 100644
--- a/IPython/nbformat/v3/nbbase.py
+++ b/IPython/nbformat/v3/nbbase.py
@@ -53,7 +53,7 @@ def from_dict(d):
 def new_output(output_type=None, output_text=None, output_png=None,
     output_html=None, output_svg=None, output_latex=None, output_json=None,
     output_javascript=None, output_jpeg=None, prompt_number=None,
-    etype=None, evalue=None, traceback=None):
+    etype=None, evalue=None, traceback=None, stream=None):
     """Create a new code cell with input and output"""
     output = NotebookNode()
     if output_type is not None:
@@ -89,6 +89,9 @@ def new_output(output_type=None, output_text=None, output_png=None,
         if traceback is not None:
             output.traceback = [unicode(frame) for frame in list(traceback)]
 
+    if output_type == u'stream':
+        output.stream = 'stdout' if stream is None else unicode(stream)
+
     return output
 
 
diff --git a/IPython/nbformat/v3/tests/nbexamples.py b/IPython/nbformat/v3/tests/nbexamples.py
index efdd38e..fa9b5cf 100644
--- a/IPython/nbformat/v3/tests/nbexamples.py
+++ b/IPython/nbformat/v3/tests/nbexamples.py
@@ -93,6 +93,7 @@ ws.cells.append(new_code_cell(
         output_text='foo\rbar\r\n'
     ),new_output(
         output_type=u'stream',
+        stream='stderr',
         output_text='\rfoo\rbar\n'
     )]
 ))