diff --git a/index.bs b/index.bs
index d36cf316..7040ee2e 100644
--- a/index.bs
+++ b/index.bs
@@ -11288,7 +11288,17 @@ with the [{{LegacyNoInterfaceObject}}] [=extended attribute=].
then set |proto| to |realm|.\[[Intrinsics]].[[{{%Error.prototype%}}]].
1. Otherwise, set |proto| to |realm|.\[[Intrinsics]].[[{{%Object.prototype%}}]].
1. Assert: Type(|proto|) is Object.
- 1. Let |interfaceProtoObj| be [=!=] [$OrdinaryObjectCreate$](|proto|).
+ 1. Let |interfaceProtoObj| be null.
+ 1. If |interface| is declared with the [{{Global}}] [=extended attribute=], or
+ |interface| is in the set of [=inherited interfaces=] of an interface
+ that is declared with the [{{Global}}] [=extended attribute=], then:
+ 1. Set |interfaceProtoObj| to [=!=] [$MakeBasicObject$](« \[[Prototype]], \[[Extensible]] »).
+ 1. Set |interfaceProtoObj|.\[[Prototype]] to |proto|.
+ 1. Set the internal methods of |interfaceProtoObj|
+ which are specific to [=immutable prototype exotic objects=]
+ to the definitions specified in
+ [=ECMA-262 Immutable prototype exotic objects=].
+ 1. Otherwise, set |interfaceProtoObj| to [=!=] [$OrdinaryObjectCreate$](|proto|).
1. If |interface| has any [=member=] declared with the [{{Unscopable}}] [=extended attribute=],
then:
@@ -11305,13 +11315,6 @@ with the [{{LegacyNoInterfaceObject}}] [=extended attribute=].
\[[Writable]]: false, \[[Enumerable]]: false,
\[[Configurable]]: true}.
1. Perform [=!=] DefinePropertyOrThrow(|interfaceProtoObj|, {{@@unscopables}}, |desc|).
- 1. If |interface| is declared with the [{{Global}}] [=extended attribute=], or
- |interface| is in the set of [=inherited interfaces=] of an interface
- that is declared with the [{{Global}}] [=extended attribute=], then:
- 1. Set the internal methods of |interfaceProtoObj|
- which are specific to [=immutable prototype exotic objects=]
- to the definitions specified in
- [=ECMA-262 Immutable prototype exotic objects=].
1. If |interface| is not declared with the [{{Global}}] [=extended attribute=], then:
1. [=Define the regular attributes=] of |interface| on |interfaceProtoObj| given |realm|.
1. [=Define the regular operations=] of |interface| on |interfaceProtoObj| given |realm|.