diff --git a/src/arch/x86/acpigen.c b/src/arch/x86/acpigen.c
index 82654e18dd..34de2bab18 100644
--- a/src/arch/x86/acpigen.c
+++ b/src/arch/x86/acpigen.c
@@ -514,7 +514,7 @@ static void acpigen_write_field_name(const char *name, uint32_t size)
  *		PMCS,   2
  *	}
  */
-void acpigen_write_field(const char *name, struct fieldlist *l, size_t count,
+void acpigen_write_field(const char *name, const struct fieldlist *l, size_t count,
 			 uint8_t flags)
 {
 	uint16_t i;
diff --git a/src/arch/x86/include/arch/acpigen.h b/src/arch/x86/include/arch/acpigen.h
index 3a74db11e9..3339ce4d92 100644
--- a/src/arch/x86/include/arch/acpigen.h
+++ b/src/arch/x86/include/arch/acpigen.h
@@ -426,7 +426,7 @@ void acpigen_write_release(const char *name);
  * Generate ACPI AML code for Field
  * This function takes input region name, fieldlist, count & flags.
  */
-void acpigen_write_field(const char *name, struct fieldlist *l, size_t count,
+void acpigen_write_field(const char *name, const struct fieldlist *l, size_t count,
 			 uint8_t flags);
 /*
  * Generate ACPI AML code for IndexField