diff --git a/vl.c b/vl.c
index b294380..4bd173f 100644
--- a/vl.c
+++ b/vl.c
@@ -236,6 +236,7 @@
 int rtc_td_hack = 0;
 #endif
 int usb_enabled = 0;
+int singlestep = 0;
 int smp_cpus = 1;
 const char *vnc_display;
 int acpi_enabled = 1;
@@ -4660,6 +4661,9 @@
             case QEMU_OPTION_bios:
                 bios_name = optarg;
                 break;
+            case QEMU_OPTION_singlestep:
+                singlestep = 1;
+                break;
             case QEMU_OPTION_S:
                 autostart = 0;
                 break;