diff --git a/pymavlink/mavutil.py b/pymavlink/mavutil.py
index 4c9c854..6077b03 100644
--- a/pymavlink/mavutil.py
+++ b/pymavlink/mavutil.py
@@ -815,7 +815,7 @@ def close(self):
 
     def recv(self,n=None):
         try:
-            data, self.last_address = self.port.recvfrom(300)
+            data, self.last_address = self.port.recvfrom(65535)
         except socket.error as e:
             if e.errno in [ errno.EAGAIN, errno.EWOULDBLOCK, errno.ECONNREFUSED ]:
                 return ""