diff --git a/msgpackstream/backend/pyc/stream.py b/msgpackstream/backend/pyc/stream.py
index <HASH>..<HASH> 100644
--- a/msgpackstream/backend/pyc/stream.py
+++ b/msgpackstream/backend/pyc/stream.py
@@ -132,7 +132,7 @@ class UnpackerIterator(object):
     
     
 
-def unpack(instream, buffersize=4000, parsers=[]):
+def unpack(instream, buffersize=5000, parsers=[]):
     '''``
         Creates an iterator instance for the unpacker
     :param instream:
diff --git a/msgpackstream/backend/python/stream.py b/msgpackstream/backend/python/stream.py
index <HASH>..<HASH> 100644
--- a/msgpackstream/backend/python/stream.py
+++ b/msgpackstream/backend/python/stream.py
@@ -496,7 +496,7 @@ class StreamUnpacker():
         
 
  
-def unpack(instream, buffersize=4000, parsers=[]):
+def unpack(instream, buffersize=5000, parsers=[]):
     '''
         Creates an iterator instance for the unpacker
     :param instream:
increased default buffersize to <I>