diff --git a/infrastructure-centred/owlps-listener/owlps-listenerd.c b/infrastructure-centred/owlps-listener/owlps-listenerd.c
index c580d29..137bae9 100644
--- a/infrastructure-centred/owlps-listener/owlps-listenerd.c
+++ b/infrastructure-centred/owlps-listener/owlps-listenerd.c
@@ -266,7 +266,9 @@ void parse_command_line(int argc, char **argv)
           print_usage() ;
           exit(0) ;
         case 'H' :
+#ifdef USE_PTHREAD
           SET_AUTOCALIBRATION_HELLO_DELAY(strtol(optarg, NULL, 0)) ;
+#endif // USE_PTHREAD
           break ;
 	case 'k' :
 #ifdef USE_PTHREAD