Index: Misc/NEWS
===================================================================
--- Misc/NEWS	(revision 70604)
+++ Misc/NEWS	(working copy)
@@ -2598,6 +2598,8 @@
 
 - The pprint module now supports sets and frozensets.
 
+- Issue #5131: The pprint module now formats defaultdicts similar to dicts.
+
 - Issue #1221598: add optional callbacks to ftplib.FTP's storbinary()
   and storlines() methods.  (Contributed by Phil Schwartz)
 
Index: Misc/ACKS
===================================================================
--- Misc/ACKS	(revision 70604)
+++ Misc/ACKS	(working copy)
@@ -148,6 +148,7 @@
 Alex Coventry
 Matthew Dixon Cowles
 Christopher A. Craig
+Nick Craig-Wood
 Laura Creighton
 Simon Cross
 Drew Csillag
@@ -787,6 +788,6 @@
 Mike Zarnstorff
 Siebren van der Zee
 Uwe Zessin
-Tarek ZiadŽ
+Tarek ZiadÂŽ
 Peter Åstrand
 Jesse Noller
Index: Lib/pprint.py
===================================================================
--- Lib/pprint.py	(revision 70604)
+++ Lib/pprint.py	(working copy)
@@ -37,6 +37,7 @@
 import sys as _sys
 
 from cStringIO import StringIO as _StringIO
+from collections import defaultdict
 
 __all__ = ["pprint","pformat","isreadable","isrecursive","saferepr",
            "PrettyPrinter"]
@@ -136,8 +137,12 @@
             return
 
         r = getattr(typ, "__repr__", None)
-        if issubclass(typ, dict) and r is dict.__repr__:
-            write('{')
+        if ((issubclass(typ, dict) and r is dict.__repr__) or
+            (issubclass(typ, defaultdict) and r is defaultdict.__repr__)):
+            if issubclass(typ, defaultdict):
+                write('defaultdict({')
+            else:
+                write('{')
             if self._indent_per_level > 1:
                 write((self._indent_per_level - 1) * ' ')
             length = _len(object)
@@ -163,7 +168,10 @@
                                       allowance + 1, context, level)
                 indent = indent - self._indent_per_level
                 del context[objid]
-            write('}')
+            if issubclass(typ, defaultdict):
+                write('})')
+            else:
+                write('}')
             return
 
         if ((issubclass(typ, list) and r is list.__repr__) or
Index: Lib/test/test_pprint.py
===================================================================
--- Lib/test/test_pprint.py	(revision 70604)
+++ Lib/test/test_pprint.py	(working copy)
@@ -414,6 +414,12 @@
         self.assertEqual(pprint.pformat(nested_list, depth=1), lv1_list)
 
 
+    def test_defaultdict(self):
+        import collections
+        dd = collections.defaultdict.fromkeys(range(10))
+        self.assertEqual(True, pprint.pformat(dd).startswith('defaultdict({'))
+        self.assertEqual(True, pprint.pformat(dd).endswith('})'))
+
 class DottedPrettyPrinter(pprint.PrettyPrinter):
 
     def format(self, object, context, maxlevels, level):