diff --git a/index.bs b/index.bs
index 5aba1f92..47fb07ef 100644
--- a/index.bs
+++ b/index.bs
@@ -12534,6 +12534,7 @@ Additionally, [=legacy platform objects=] have internal methods as defined in:
             1.  [=Invoke the indexed property setter=] with |P| and |V|.
             1.  Return <emu-val>true</emu-val>.
         1.  If |O| [=implements=] an interface with a [=named property setter=]
+            and the [{{OverrideBuiltins}}] [=extended attribute=],
             and <a abstract-op>Type</a>(|P|) is String, then:
             1.  [=Invoke the named property setter=] with |P| and |V|.
             1.  Return <emu-val>true</emu-val>.