diff --git a/hw/isa/piix3.c b/hw/isa/piix3.c
index 117024e450..7240c91440 100644
--- a/hw/isa/piix3.c
+++ b/hw/isa/piix3.c
@@ -48,7 +48,7 @@ static void piix3_set_irq_level_internal(PIIX3State *piix3, int pirq, int level)
     uint64_t mask;
 
     pic_irq = piix3->dev.config[PIIX_PIRQCA + pirq];
-    if (pic_irq >= PIIX_NUM_PIC_IRQS) {
+    if (pic_irq >= ISA_NUM_IRQS) {
         return;
     }
 
@@ -62,7 +62,7 @@ static void piix3_set_irq_level(PIIX3State *piix3, int pirq, int level)
     int pic_irq;
 
     pic_irq = piix3->dev.config[PIIX_PIRQCA + pirq];
-    if (pic_irq >= PIIX_NUM_PIC_IRQS) {
+    if (pic_irq >= ISA_NUM_IRQS) {
         return;
     }
 
@@ -83,7 +83,7 @@ static PCIINTxRoute piix3_route_intx_pin_to_irq(void *opaque, int pin)
     int irq = piix3->dev.config[PIIX_PIRQCA + pin];
     PCIINTxRoute route;
 
-    if (irq < PIIX_NUM_PIC_IRQS) {
+    if (irq < ISA_NUM_IRQS) {
         route.mode = PCI_INTX_ENABLED;
         route.irq = irq;
     } else {
@@ -115,7 +115,7 @@ static void piix3_write_config(PCIDevice *dev,
 
         pci_bus_fire_intx_routing_notifier(pci_get_bus(&piix3->dev));
         piix3_update_irq_levels(piix3);
-        for (pic_irq = 0; pic_irq < PIIX_NUM_PIC_IRQS; pic_irq++) {
+        for (pic_irq = 0; pic_irq < ISA_NUM_IRQS; pic_irq++) {
             piix3_set_irq_pic(piix3, pic_irq);
         }
     }
diff --git a/include/hw/southbridge/piix.h b/include/hw/southbridge/piix.h
index 278171752f..2317bb7974 100644
--- a/include/hw/southbridge/piix.h
+++ b/include/hw/southbridge/piix.h
@@ -27,7 +27,6 @@
  */
 #define PIIX_RCR_IOPORT 0xcf9
 
-#define PIIX_NUM_PIC_IRQS       16      /* i8259 * 2 */
 #define PIIX_NUM_PIRQS          4ULL    /* PIRQ[A-D] */
 
 struct PIIXState {
@@ -39,10 +38,10 @@ struct PIIXState {
      * So one PIC level is tracked by PIIX_NUM_PIRQS bits.
      *
      * PIRQ is mapped to PIC pins, we track it by
-     * PIIX_NUM_PIRQS * PIIX_NUM_PIC_IRQS = 64 bits with
+     * PIIX_NUM_PIRQS * ISA_NUM_IRQS = 64 bits with
      * pic_irq * PIIX_NUM_PIRQS + pirq
      */
-#if PIIX_NUM_PIC_IRQS * PIIX_NUM_PIRQS > 64
+#if ISA_NUM_IRQS * PIIX_NUM_PIRQS > 64
 #error "unable to encode pic state in 64bit in pic_levels."
 #endif
     uint64_t pic_levels;