diff --git a/hw/pc_piix.c b/hw/pc_piix.c
index 32a105736d..12359a75c9 100644
--- a/hw/pc_piix.c
+++ b/hw/pc_piix.c
@@ -104,6 +104,7 @@ static void pc_init1(ram_addr_t ram_size,
         pci_bus = i440fx_init(&i440fx_state, &piix3_devfn, isa_irq, ram_size);
     } else {
         pci_bus = NULL;
+        i440fx_state = NULL;
         isa_bus_new(NULL);
     }
     isa_bus_irqs(isa_irq);