diff --git a/drivers/acpi/sbs.c b/drivers/acpi/sbs.c
index f136c7d..1194105 100644
--- a/drivers/acpi/sbs.c
+++ b/drivers/acpi/sbs.c
@@ -888,7 +888,7 @@
 #endif
 }
 
-void acpi_sbs_callback(void *context)
+static void acpi_sbs_callback(void *context)
 {
 	int id;
 	struct acpi_sbs *sbs = context;