diff --git a/spec.html b/spec.html
index 542207d7f5f..9bdd600dc92 100644
--- a/spec.html
+++ b/spec.html
@@ -11785,8 +11785,10 @@ <h1>[[Set]] ( _P_, _V_, _Receiver_ )</h1>
           1. If Type(_P_) is String, then
             1. Let _numericIndex_ be ! CanonicalNumericIndexString(_P_).
             1. If _numericIndex_ is not *undefined*, then
-              1. Perform ? IntegerIndexedElementSet(_O_, _numericIndex_, _V_).
-              1. Return *true*.
+              1. If ! SameValue(_O_, _Receiver_) is *true*, then
+                1. Perform ? IntegerIndexedElementSet(_O_, _numericIndex_, _V_).
+                1. Return *true*.
+              1. If ! IsValidIntegerIndex(_O_, _numericIndex_) is *false*, return *true*.
           1. Return ? OrdinarySet(_O_, _P_, _V_, _Receiver_).
         </emu-alg>
       </emu-clause>