18w48a ignoring server-port from server.properties

I have the following in my server.properties:

server-port=25569

However the server is starting on the default port:

[11:23:34] [Server thread/INFO]: Starting minecraft server version 18w48a
[11:23:34] [Server thread/INFO]: Loading properties
[11:23:34] [Server thread/INFO]: Default game type: SURVIVAL
[11:23:34] [Server thread/INFO]: Generating keypair
[11:23:35] [Server thread/INFO]: Starting Minecraft server on *:25565