diff --git a/hw/isa/piix4.c b/hw/isa/piix4.c
index 3c3c7a094c..9c8b6c98ab 100644
--- a/hw/isa/piix4.c
+++ b/hw/isa/piix4.c
@@ -45,7 +45,7 @@
 struct PIIX4State {
     PCIDevice dev;
     qemu_irq cpu_intr;
-    qemu_irq *isa;
+    qemu_irq *isa_irqs_in;
 
     MC146818RtcState rtc;
     PCIIDEState ide;
@@ -75,7 +75,7 @@ static void piix4_set_irq(void *opaque, int irq_num, int level)
                 pic_level |= pci_bus_get_irq_level(bus, i);
             }
         }
-        qemu_set_irq(s->isa[pic_irq], pic_level);
+        qemu_set_irq(s->isa_irqs_in[pic_irq], pic_level);
     }
 }
 
@@ -201,10 +201,10 @@ static void piix4_realize(PCIDevice *dev, Error **errp)
 
     /* initialize i8259 pic */
     i8259_out_irq = qemu_allocate_irqs(piix4_request_i8259_irq, s, 1);
-    s->isa = i8259_init(isa_bus, *i8259_out_irq);
+    s->isa_irqs_in = i8259_init(isa_bus, *i8259_out_irq);
 
     /* initialize ISA irqs */
-    isa_bus_register_input_irqs(isa_bus, s->isa);
+    isa_bus_register_input_irqs(isa_bus, s->isa_irqs_in);
 
     /* initialize pit */
     i8254_pit_init(isa_bus, 0x40, 0, NULL);
@@ -236,7 +236,7 @@ static void piix4_realize(PCIDevice *dev, Error **errp)
     if (!qdev_realize(DEVICE(&s->pm), BUS(pci_bus), errp)) {
         return;
     }
-    qdev_connect_gpio_out(DEVICE(&s->pm), 0, s->isa[9]);
+    qdev_connect_gpio_out(DEVICE(&s->pm), 0, s->isa_irqs_in[9]);
 
     pci_bus_irqs(pci_bus, piix4_set_irq, s, PIIX_NUM_PIRQS);
 }