diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 71fe552c83..a217c7f7a6 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -3127,6 +3127,11 @@ static void spapr_set_ic_mode(Object *obj, const char *value, Error **errp)
 {
     sPAPRMachineState *spapr = SPAPR_MACHINE(obj);
 
+    if (SPAPR_MACHINE_GET_CLASS(spapr)->legacy_irq_allocation) {
+        error_setg(errp, "This machine only uses the legacy XICS backend, don't pass ic-mode");
+        return;
+    }
+
     /* The legacy IRQ backend can not be set */
     if (strcmp(value, "xics") == 0) {
         spapr->irq = &spapr_irq_xics;