diff --git a/hw/acpi/aml-build.c b/hw/acpi/aml-build.c
index b4fff5f0a8..f58eb0123a 100644
--- a/hw/acpi/aml-build.c
+++ b/hw/acpi/aml-build.c
@@ -427,6 +427,15 @@ Aml *aml_arg(int pos)
     return var;
 }
 
+/* ACPI 2.0a: 17.2.4.4 Type 2 Opcodes Encoding: DefToInteger */
+Aml *aml_to_integer(Aml *arg)
+{
+    Aml *var = aml_opcode(0x99 /* ToIntegerOp */);
+    aml_append(var, arg);
+    build_append_byte(var->buf, 0x00 /* NullNameOp */);
+    return var;
+}
+
 /* ACPI 1.0b: 16.2.5.4 Type 2 Opcodes Encoding: DefStore */
 Aml *aml_store(Aml *val, Aml *target)
 {
diff --git a/include/hw/acpi/aml-build.h b/include/hw/acpi/aml-build.h
index 81326bd9b7..c3d3fd5c8f 100644
--- a/include/hw/acpi/aml-build.h
+++ b/include/hw/acpi/aml-build.h
@@ -224,6 +224,7 @@ Aml *aml_name_decl(const char *name, Aml *val);
 Aml *aml_return(Aml *val);
 Aml *aml_int(const uint64_t val);
 Aml *aml_arg(int pos);
+Aml *aml_to_integer(Aml *arg);
 Aml *aml_store(Aml *val, Aml *target);
 Aml *aml_and(Aml *arg1, Aml *arg2);
 Aml *aml_or(Aml *arg1, Aml *arg2);