diff --git a/spec/numberformat.html b/spec/numberformat.html
index cf719e7d..54f549f4 100644
--- a/spec/numberformat.html
+++ b/spec/numberformat.html
@@ -618,6 +618,23 @@ <h1>get Intl.NumberFormat.prototype.format</h1>
       </emu-alg>
     </emu-clause>
 
+    <emu-clause id="sec-intl.numberformat.prototype.formattoparts">
+      <h1>Intl.NumberFormat.prototype.formatToParts ( [ _value_ ] )</h1>
+
+      <p>
+        When the *Intl.NumberFormat.prototype.formatToParts* is called with an optional argument _value_, the following steps are taken:
+      </p>
+
+      <emu-alg>
+        1. Let _nf_ be *this* value.
+        1. If Type(_nf_) is not Object, throw a *TypeError* exception.
+        1. If _nf_ does not have an [[initializedNumberFormat]] internal slot, throw a *TypeError* exception.
+        1. If _value_ is not provided, let _value_ be *undefined*.
+        1. Let _x_ be ? ToNumber(_value_).
+        1. Return ? FormatNumberToParts(_nf_, _x_).
+      </emu-alg>
+    </emu-clause>
+
     <emu-clause id="sec-intl.numberformat.prototype.resolvedoptions">
       <h1>Intl.NumberFormat.prototype.resolvedOptions ()</h1>