diff --git a/arch/x86/include/asm/acpi.h b/arch/x86/include/asm/acpi.h
index 8d0ec9df1cbeb53894f47454cd1391b297e6086c..44f5d79d51056b036e7ef4536d7bfe340dae9747 100644
--- a/arch/x86/include/asm/acpi.h
+++ b/arch/x86/include/asm/acpi.h
@@ -49,7 +49,7 @@ extern int acpi_fix_pin2_polarity;
 extern int acpi_disable_cmcff;
 
 extern u8 acpi_sci_flags;
-extern int acpi_sci_override_gsi;
+extern u32 acpi_sci_override_gsi;
 void acpi_pic_sci_set_trigger(unsigned int, u16);
 
 struct device;
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 56752b48e4803edc7237996d345edd038a6c6935..5a12cadbf019a2891cb5eb9bbde992fe671a1ef8 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -68,8 +68,9 @@ int acpi_ioapic;
 int acpi_strict;
 int acpi_disable_cmcff;
 
+/* ACPI SCI override configuration */
 u8 acpi_sci_flags __initdata;
-int acpi_sci_override_gsi __initdata;
+u32 acpi_sci_override_gsi __initdata = INVALID_ACPI_IRQ;
 int acpi_skip_timer_override __initdata;
 int acpi_use_timer_override __initdata;
 int acpi_fix_pin2_polarity __initdata;
@@ -1209,7 +1210,7 @@ static int __init acpi_parse_madt_ioapic_entries(void)
 	 * If BIOS did not supply an INT_SRC_OVR for the SCI
 	 * pretend we got one so we can set the SCI flags.
 	 */
-	if (!acpi_sci_override_gsi)
+	if (acpi_sci_override_gsi == INVALID_ACPI_IRQ)
 		acpi_sci_ioapic_setup(acpi_gbl_FADT.sci_interrupt, 0, 0,
 				      acpi_gbl_FADT.sci_interrupt);