diff --git a/vl.c b/vl.c
index ab8f152..194c6f7 100644
--- a/vl.c
+++ b/vl.c
@@ -381,6 +381,10 @@
             .name = "kvm-type",
             .type = QEMU_OPT_STRING,
             .help = "Specifies the KVM virtualization mode (HV, PR)",
+        },{
+            .name = PC_MACHINE_MAX_RAM_BELOW_4G,
+            .type = QEMU_OPT_SIZE,
+            .help = "maximum ram below the 4G boundary (32bit boundary)",
         },
         { /* End of list */ }
     },