diff --git a/infrastructure-centred/owlps-listener/owlps-listenerd.c b/infrastructure-centred/owlps-listener/owlps-listenerd.c
index f462da6..c9256e4 100644
--- a/infrastructure-centred/owlps-listener/owlps-listenerd.c
+++ b/infrastructure-centred/owlps-listener/owlps-listenerd.c
@@ -676,7 +676,7 @@ void read_packet(u_char *args, const struct pcap_pkthdr *header,
           if (GET_VERBOSE())
             {
               printf("\nAutocalibration packet received.") ;
-              if (uses_autocalibration_request_port)
+              if (! uses_autocalibration_request_port)
                 printf(".. on the wrong port!") ;
               putchar('\n') ;
             }