Actuall use [[PreventExtensions]]

spec.html

@@ -14618,7 +14618,7 @@ <h1>
       <h1>TypedArray Exotic Objects</h1>
       <p>A TypedArray is an exotic object that performs special handling of integer index property keys.</p>
       <p>TypedArrays have the same internal slots as ordinary objects and additionally [[ViewedArrayBuffer]], [[ArrayLength]], [[ByteOffset]], [[ContentType]], and [[TypedArrayName]] internal slots.</p>
-      <p>An object is a <dfn id="typedarray" oldids="integer-indexed-exotic-object" variants="TypedArrays">TypedArray</dfn> if its [[GetOwnProperty]], [[HasProperty]], [[DefineOwnProperty]], [[Get]], [[Set]], [[Delete]], and [[OwnPropertyKeys]] internal methods use the definitions in this section, and its other essential internal methods use the definitions found in <emu-xref href="#sec-ordinary-object-internal-methods-and-internal-slots"></emu-xref>. These methods are installed by TypedArrayCreate.</p>
+      <p>An object is a <dfn id="typedarray" oldids="integer-indexed-exotic-object" variants="TypedArrays">TypedArray</dfn> if its [[PreventExtensions]], [[GetOwnProperty]], [[HasProperty]], [[DefineOwnProperty]], [[Get]], [[Set]], [[Delete]], and [[OwnPropertyKeys]], internal methods use the definitions in this section, and its other essential internal methods use the definitions found in <emu-xref href="#sec-ordinary-object-internal-methods-and-internal-slots"></emu-xref>. These methods are installed by TypedArrayCreate.</p>
 
       <emu-clause id="sec-typedarray-preventextensions" type="internal method">
         <h1>[[PreventExtensions]] ( ): a normal completion containing a Boolean</h1>
@@ -14859,6 +14859,7 @@ <h1>
         <emu-alg>
           1. Let _internalSlotsList_ be « [[Prototype]], [[Extensible]], [[ViewedArrayBuffer]], [[TypedArrayName]], [[ContentType]], [[ByteLength]], [[ByteOffset]], [[ArrayLength]] ».
           1. Let _A_ be MakeBasicObject(_internalSlotsList_).
+          1. Set _A_.[[PreventExtensions]] as specified in <emu-xref href="#sec-typedarray-preventextensions"></emu-xref>.
           1. Set _A_.[[GetOwnProperty]] as specified in <emu-xref href="#sec-typedarray-getownproperty"></emu-xref>.
           1. Set _A_.[[HasProperty]] as specified in <emu-xref href="#sec-typedarray-hasproperty"></emu-xref>.
           1. Set _A_.[[DefineOwnProperty]] as specified in <emu-xref href="#sec-typedarray-defineownproperty"></emu-xref>.