diff --git a/reference/mongodb/functions/bson/tophp.xml b/reference/mongodb/functions/bson/tophp.xml
index f600175012..7398d6a309 100644
--- a/reference/mongodb/functions/bson/tophp.xml
+++ b/reference/mongodb/functions/bson/tophp.xml
@@ -19,6 +19,14 @@
    The <parameter>typeMap</parameter> paramater may be used to control the PHP
    types used for converting BSON arrays and documents (both root and embedded).
   </para>
+  <warning>
+   <simpara>
+    Fields containing deprecated BSON types (i.e. undefined, symbol, DBPointer)
+    are ignored when converting BSON to PHP. This can result in a loss of data
+    when round-tripping BSON documents through PHP, as any fields containing a
+    deprecated type will be silently dropped.
+   </simpara>
+  </warning>
  </refsect1>
 
  <refsect1 role="parameters">
@@ -75,6 +83,18 @@
       </row>
      </thead>
      <tbody>
+      <row>
+       <entry>1.3.2</entry>
+       <entry>
+        <para>
+         <classname>MongoDB\Driver\Exception\UnexpectedValueException</classname>
+         is no longer thrown if the input contains an unsupported, deprecated
+         BSON type. Such types will be ignored (as they were in versions before
+         1.3.0), although the driver will now log a warning to the debug log
+         (see: <link linkend="ini.mongodb.debug">mongodb.debug</link>).
+        </para>
+       </entry>
+      </row>
       <row>
        <entry>1.3.0</entry>
        <entry>