diff --git a/src/acpi/acpi.c b/src/acpi/acpi.c
index 78135d79dd..ce1453825f 100644
--- a/src/acpi/acpi.c
+++ b/src/acpi/acpi.c
@@ -1854,7 +1854,7 @@ static void acpidump_print(void *table_ptr)
 	printk(BIOS_SPEW, "\n");
 }
 
-unsigned long write_acpi_tables(unsigned long start)
+unsigned long write_acpi_tables(const unsigned long start)
 {
 	unsigned long current;
 	acpi_rsdp_t *rsdp;
diff --git a/src/include/acpi/acpi.h b/src/include/acpi/acpi.h
index 09e12115ba..d3f209a44e 100644
--- a/src/include/acpi/acpi.h
+++ b/src/include/acpi/acpi.h
@@ -1335,7 +1335,7 @@ unsigned long fw_cfg_acpi_tables(unsigned long start);
 
 /* These are implemented by the target port or north/southbridge. */
 void preload_acpi_dsdt(void);
-unsigned long write_acpi_tables(unsigned long addr);
+unsigned long write_acpi_tables(const unsigned long addr);
 unsigned long acpi_fill_madt(unsigned long current);
 
 void acpi_fill_fadt(acpi_fadt_t *fadt);