Is there away to stop the int-ws:outbound-gateway from setting the a SOAP Action in the outgoing SOAP header

We're getting an empty string value, if we inspect the message in TCPMon

SOAPAction: ""

The web service I want to call expects no SOAPAction at all.

There seems to be plenty of examples of how to set a specific value into the SOAPAction (using a header enricher) but none showing how to remove.

We're using Spring Integration 2.1.2.RELEASE