WebSocketFlowHandler and AbruptTerminationException

[Albert]

When I redeploy my application to heroku, I'm seeing the following akka AbruptTerminationException exceptions (which are being logged by the WebSocketFlowHandler)

[info] - play.core.server.AkkaHttpServer - Stopping server... 

[info] - akka.actor.CoordinatedShutdown - Starting coordinated shutdown from JVM shutdown hook 

[error] - play.core.server.common.WebSocketFlowHandler - WebSocket flow threw exception 

akka.stream.AbruptTerminationException: Processor actor [Actor[akka://application/user/StreamSupervisor-0/flow-693-0-unnamed#-1777448355]] terminated abruptly

Is there a shutdown hook where I can more gracefully handle this shutdown?