diff --git a/vl.c b/vl.c
index fd89e50da7..a3e43ad9a7 100644
--- a/vl.c
+++ b/vl.c
@@ -5377,6 +5377,9 @@ int main(int argc, char **argv, char **envp)
             case QEMU_OPTION_serial:
                 add_device_config(DEV_SERIAL, optarg);
                 default_serial = 0;
+                if (strncmp(optarg, "mon:", 4) == 0) {
+                    default_monitor = 0;
+                }
                 break;
             case QEMU_OPTION_watchdog:
                 if (watchdog) {
@@ -5395,10 +5398,16 @@ int main(int argc, char **argv, char **envp)
             case QEMU_OPTION_virtiocon:
                 add_device_config(DEV_VIRTCON, optarg);
                 default_virtcon = 0;
+                if (strncmp(optarg, "mon:", 4) == 0) {
+                    default_monitor = 0;
+                }
                 break;
             case QEMU_OPTION_parallel:
                 add_device_config(DEV_PARALLEL, optarg);
                 default_parallel = 0;
+                if (strncmp(optarg, "mon:", 4) == 0) {
+                    default_monitor = 0;
+                }
                 break;
             case QEMU_OPTION_debugcon:
                 add_device_config(DEV_DEBUGCON, optarg);