diff --git a/include/acpi/actypes.h b/include/acpi/actypes.h
index a9d33e8c33b7..63fd7f5e9fb3 100644
--- a/include/acpi/actypes.h
+++ b/include/acpi/actypes.h
@@ -525,6 +525,7 @@ typedef u64 acpi_integer;
 #define ACPI_CAST_PTR(t, p)             ((t *) (acpi_uintptr_t) (p))
 #define ACPI_CAST_INDIRECT_PTR(t, p)    ((t **) (acpi_uintptr_t) (p))
 #define ACPI_ADD_PTR(t, a, b)           ACPI_CAST_PTR (t, (ACPI_CAST_PTR (u8, (a)) + (acpi_size)(b)))
+#define ACPI_SUB_PTR(t, a, b)           ACPI_CAST_PTR (t, (ACPI_CAST_PTR (u8, (a)) - (acpi_size)(b)))
 #define ACPI_PTR_DIFF(a, b)             (acpi_size) (ACPI_CAST_PTR (u8, (a)) - ACPI_CAST_PTR (u8, (b)))
 
 /* Pointer/Integer type conversions */