diff --git a/hw/xtensa_sim.c b/hw/xtensa_sim.c
index ed38bd425d7895f6a7ad95792a999ad137b6bdd8..831460b7c4840355e9ad63a3b8a4e6abb4fbf15c 100644
--- a/hw/xtensa_sim.c
+++ b/hw/xtensa_sim.c
@@ -111,6 +111,7 @@ static void xtensa_sim_init(ram_addr_t ram_size,
 static QEMUMachine xtensa_sim_machine = {
     .name = "sim",
     .desc = "sim machine (" XTENSA_DEFAULT_CPU_MODEL ")",
+    .is_default = true,
     .init = xtensa_sim_init,
     .max_cpus = 4,
 };