diff --git a/drivers/acpi/processor_pdc.c b/drivers/acpi/processor_pdc.c
index 1a8591e9a9bf..994091bd52de 100644
--- a/drivers/acpi/processor_pdc.c
+++ b/drivers/acpi/processor_pdc.c
@@ -19,6 +19,7 @@ static void acpi_set_pdc_bits(u32 *buf)
 {
 	buf[0] = ACPI_PDC_REVISION_ID;
 	buf[1] = 1;
+	buf[2] = 0;
 
 	/* Twiddle arch-specific bits needed for _PDC */
 	arch_acpi_set_proc_cap_bits(&buf[2]);