diff --git a/spec.html b/spec.html
index 9823aaa49e..0ce093de56 100644
--- a/spec.html
+++ b/spec.html
@@ -5622,11 +5622,11 @@ <h1>
       <h1>
         ToLength (
           _argument_: an ECMAScript language value,
-        ): either a normal completion containing an integral Number or a throw completion
+        ): either a normal completion containing a non-negative integral Number or a throw completion
       </h1>
       <dl class="header">
         <dt>description</dt>
-        <dd>It clamps and truncates _argument_ to an integral Number suitable for use as the length of an array-like object.</dd>
+        <dd>It clamps and truncates _argument_ to a non-negative integral Number suitable for use as the length of an array-like object.</dd>
       </dl>
       <emu-alg>
         1. Let _len_ be ? ToIntegerOrInfinity(_argument_).