diff --git a/arch/x86/core/pcie.c b/arch/x86/core/pcie.c
index b791ace6056..6bf284bff2c 100644
--- a/arch/x86/core/pcie.c
+++ b/arch/x86/core/pcie.c
@@ -81,7 +81,7 @@ u32_t pcie_msi_map(unsigned int irq)
 
 u16_t pcie_msi_mdr(unsigned int irq)
 {
-	unsigned char vector = _irq_to_interrupt_vector[irq];
+	unsigned char vector = Z_IRQ_TO_INTERRUPT_VECTOR(irq);
 
 	return 0x4000U | vector;  /* edge triggered */
 }