diff --git a/src/system/kernel/arch/x86/irq_routing_table.h b/src/system/kernel/arch/x86/irq_routing_table.h
index 3794588ca8..3db7980ccd 100644
--- a/src/system/kernel/arch/x86/irq_routing_table.h
+++ b/src/system/kernel/arch/x86/irq_routing_table.h
@@ -45,7 +45,7 @@ struct irq_descriptor {
 typedef struct acpi_prt {
 	uint32			length;
 	uint32			pin;
-	int				address;		// here for 64-bit alignment
+	uint64			address;		// here for 64-bit alignment
 	uint32			sourceIndex;
 	char			source[4];		// pad to 64 bits so sizeof() works in
 									// all cases