diff --git a/libagent/win_server.py b/libagent/win_server.py
index c059402..1127982 100644
--- a/libagent/win_server.py
+++ b/libagent/win_server.py
@@ -182,6 +182,8 @@ def recv(self, size):
         except win32api.error as e:
             if e.winerror == winerror.ERROR_BROKEN_PIPE:
                 return None
+            if e.winerror == winerror.ERROR_MORE_DATA:
+                return rbuf
             raise
 
     def send(self, data):