fix attribute error
diff --git a/Lib/asyncore.py b/Lib/asyncore.py
index f790c8a..d647606 100644
--- a/Lib/asyncore.py
+++ b/Lib/asyncore.py
@@ -54,7 +54,8 @@
 
 import os
 from errno import EALREADY, EINPROGRESS, EWOULDBLOCK, ECONNRESET, EINVAL, \
-     ENOTCONN, ESHUTDOWN, EINTR, EISCONN, EBADF, ECONNABORTED, EPIPE, errorcode
+     ENOTCONN, ESHUTDOWN, EINTR, EISCONN, EBADF, ECONNABORTED, EPIPE, EAGAIN, \
+     errorcode
 
 _DISCONNECTED = frozenset((ECONNRESET, ENOTCONN, ESHUTDOWN, ECONNABORTED, EPIPE,
                            EBADF))