diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 7422c05254..5d8b8c9e53 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -4290,6 +4290,7 @@ static void spapr_machine_class_init(ObjectClass *oc, void *data)
     smc->default_caps.caps[SPAPR_CAP_NESTED_KVM_HV] = SPAPR_CAP_OFF;
     spapr_caps_add_properties(smc, &error_abort);
     smc->irq = &spapr_irq_xics;
+    smc->dr_phb_enabled = true;
 }
 
 static const TypeInfo spapr_machine_info = {
@@ -4361,6 +4362,7 @@ static void spapr_machine_3_1_class_options(MachineClass *mc)
 
     mc->default_cpu_type = POWERPC_CPU_TYPE_NAME("power8_v2.0");
     smc->update_dt_enabled = false;
+    smc->dr_phb_enabled = false;
 }
 
 DEFINE_SPAPR_MACHINE(3_1, "3.1", false);