diff --git a/lib/ClusterShell/Communication.py b/lib/ClusterShell/Communication.py
index 7a004635..23b20756 100644
--- a/lib/ClusterShell/Communication.py
+++ b/lib/ClusterShell/Communication.py
@@ -229,6 +229,8 @@ def ev_read(self, worker, node, sname, msg):
 
         try:
             self._parser.feed(msg + b'\n')
+            if hasattr(self._parser, 'flush'):  # GH#556
+                self._parser.flush()
         except SAXParseException as ex:
             self.logger.error("SAXParseException: %s: %s", ex.getMessage(), msg)
             # Warning: do not send malformed raw message back