diff --git a/hw/intc/i8259_common.c b/hw/intc/i8259_common.c
index 3a850b0c66..d9a5e8b217 100644
--- a/hw/intc/i8259_common.c
+++ b/hw/intc/i8259_common.c
@@ -70,10 +70,11 @@ static int pic_dispatch_post_load(void *opaque, int version_id)
 static void pic_common_realize(DeviceState *dev, Error **errp)
 {
     PICCommonState *s = PIC_COMMON(dev);
+    ISADevice *isa = ISA_DEVICE(dev);
 
-    isa_register_ioport(NULL, &s->base_io, s->iobase);
+    isa_register_ioport(isa, &s->base_io, s->iobase);
     if (s->elcr_addr != -1) {
-        isa_register_ioport(NULL, &s->elcr_io, s->elcr_addr);
+        isa_register_ioport(isa, &s->elcr_io, s->elcr_addr);
     }
 
     qdev_set_legacy_instance_id(dev, s->iobase, 1);