diff --git a/IPython/lib/pretty.py b/IPython/lib/pretty.py
index 83cf094..4c18089 100644
--- a/IPython/lib/pretty.py
+++ b/IPython/lib/pretty.py
@@ -84,7 +84,7 @@ import re
 import datetime
 from collections import deque
 
-from IPython.utils.py3compat import PY3, PYPY, cast_unicode
+from IPython.utils.py3compat import PYPY, cast_unicode
 from IPython.utils.encoding import get_stream_enc
 
 from io import StringIO
@@ -108,15 +108,7 @@ def _safe_getattr(obj, attr, default=None):
     except Exception:
         return default
 
-if PY3:
-    CUnicodeIO = StringIO
-else:
-    class CUnicodeIO(StringIO):
-        """StringIO that casts str to unicode on Python 2"""
-        def write(self, text):
-            return super(CUnicodeIO, self).write(
-                cast_unicode(text, encoding=get_stream_enc(sys.stdout)))
-
+CUnicodeIO = StringIO
 
 def pretty(obj, verbose=False, max_width=79, newline='\n', max_seq_length=MAX_SEQ_LENGTH):
     """