diff --git a/reference/mongodb/bson/utcdatetime/construct.xml b/reference/mongodb/bson/utcdatetime/construct.xml
index 80fe7b2a73..7f9a183337 100644
--- a/reference/mongodb/bson/utcdatetime/construct.xml
+++ b/reference/mongodb/bson/utcdatetime/construct.xml
@@ -71,7 +71,9 @@
          The <parameter>milliseconds</parameter> argument is optional and
          defaults to &null; (i.e. current time). The argument also accepts a
          <classname>DateTimeInterface</classname>, which may be used to derive
-         the number of milliseconds since the Unix epoch.
+         the number of milliseconds since the Unix epoch. Previously, only
+         <type>integer</type>, <type>float</type>, and <type>string</type> types
+         were accepted.
         </para>
        </entry>
       </row>