diff --git a/src/include/86box/pci.h b/src/include/86box/pci.h
index d2348ba02..097fcf502 100644
--- a/src/include/86box/pci.h
+++ b/src/include/86box/pci.h
@@ -110,6 +110,7 @@
 #define PCI_CARD_MAX              (PCI_CARDS_NUM - 1)
 /* The number of PCI card INT pins - always at 4 per the PCI specification. */
 #define PCI_INT_PINS_NUM          4
+#define PCI_INT_PINS_MAX          (PCI_INT_PINS_NUM - 1)
 /* The base for MIRQ lines accepted by pci_irq(). */
 #define PCI_MIRQ_BASE             PCI_CARDS_NUM
 /* PCI MIRQ lines (currently 8, this many are needed by the ALi M1543(C). */
@@ -154,7 +155,7 @@
 #define pci_set_mirq(mirq, level, irq_state) \
         pci_irq(PCI_MIRQ_BASE | (mirq), 0, level, 1, irq_state)
 #define pci_set_iirq(pci_int, irq_state) \
-        pci_irq(PCI_IIRQ_BASE | 0, pci_int, 0, 1, irq_state)
+        pci_irq(PCI_IIRQ_BASE | (pci_int), 0, 0, 1, irq_state)
 #define pci_set_dirq(irq, irq_state) \
         pci_irq(PCI_DIRQ_BASE | (irq), 0, 1, 1, irq_state)
 #define pci_set_irq(slot, pci_int, irq_state) \
@@ -162,7 +163,7 @@
 #define pci_clear_mirq(mirq, level, irq_state) \
         pci_irq(PCI_MIRQ_BASE | (mirq), 0, level, 0, irq_state)
 #define pci_clear_iirq(pci_int, irq_state) \
-        pci_irq(PCI_IIRQ_BASE | 0, pci_int, 0, 0, irq_state)
+        pci_irq(PCI_IIRQ_BASE | (pci_int), 0, 0, 0, irq_state)
 #define pci_clear_dirq(dirq, irq_state) \
         pci_irq(PCI_DIRQ_BASE | (irq), 0, 1, 0, irq_state)
 #define pci_clear_irq(slot, pci_int, irq_state) \
diff --git a/src/pci.c b/src/pci.c
index 6fb84010d..3468d7949 100644
--- a/src/pci.c
+++ b/src/pci.c
@@ -206,16 +206,13 @@ pci_irq(uint8_t slot, uint8_t pci_int, int level, int set, uint8_t *irq_state)
             break;
         case (PCI_IIRQ_BASE | 0x00) ... (PCI_IIRQ_BASE | PCI_IIRQ_MAX):
             /* PCI internal routing. */
-            if (!last_pci_card || (pci_flags & FLAG_NO_IRQ_STEERING))
-                return;
+            slot = (slot - 1) & PCI_INT_PINS_MAX;
 
-            irq_routing = (pci_int_index - PCI_IIRQ_BASE) & PCI_IRQ_MAX;
-
-            irq_line    = pci_irqs[irq_routing];
+            irq_line    = pci_irqs[slot];
 
             /* Ignore what was provided to us as a parameter and override it with whatever
                the chipset is set to. */
-            level       = !!pci_irq_level[irq_routing];
+            level       = !!pci_irq_level[slot];
             break;
         case (PCI_MIRQ_BASE | 0x00) ... (PCI_MIRQ_BASE | PCI_MIRQ_MAX):
             /* MIRQ */