diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c
index f098e25b6b41..86c10599d9f8 100644
--- a/drivers/acpi/acpi_processor.c
+++ b/drivers/acpi/acpi_processor.c
@@ -670,7 +670,7 @@ static acpi_status __init acpi_processor_ids_walk(acpi_handle handle,
 
 }
 
-void __init acpi_processor_check_duplicates(void)
+static void __init acpi_processor_check_duplicates(void)
 {
 	/* check the correctness for all processors in ACPI namespace */
 	acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,