diff -r 262204877004 Lib/asynchat.py
--- a/Lib/asynchat.py	Mon Apr 14 11:20:45 2014 -0400
+++ b/Lib/asynchat.py	Wed Apr 16 15:17:03 2014 -0400
@@ -181,6 +181,8 @@
         self.close()
 
     def push (self, data):
+        if not isinstance(data, bytes):
+            raise TypeError("data must be a bytes object")
         sabs = self.ac_out_buffer_size
         if len(data) > sabs:
             for i in range(0, len(data), sabs):