AltSoftSerial echos also to hardware serial

Hi, I've created a sketch running on a pro mini which uses the hardware serial to connect to the computer via FTDI and am using the AltSoftSerial library to connect to an ESP8266. For some reason all the communications going through to the ESP are also getting echoed to the serial monitor. I couldn't find any mention of this anywhere. Is this normal operation of this library? Is there any way to disable it?

Thanks,

No it's not normal. Show us your code please. Use [ code ] tags.

Turns out when copying over some my code from a sketch intended to run directly on the ESP module I failed to change an internal serial print line which was now echoing to the main serial.