diff --git a/appendices/migration55.xml b/appendices/migration55.xml
index 6fd7c0d0a6..bbc3c71bd9 100644
--- a/appendices/migration55.xml
+++ b/appendices/migration55.xml
@@ -423,6 +423,17 @@ String dereferencing: P
    </para>
   </sect2>
 
+  <sect2 xml:id="migration55.new-features.non-scalar-iterator-keys">
+   <title><link linkend="control-structures.foreach"><literal>foreach</literal></link> now supports non-scalar keys</title>
+
+   <para>
+    <link linkend="control-structures.foreach">foreach</link> now supports
+    keys of any type. While non-scalar keys cannot occur in native PHP arrays,
+    it is possible for <methodname>Iterator::key</methodname> to return a
+    value of any type, and this will now be handled correctly.
+   </para>
+  </sect2>
+
   <sect2 xml:id="migration55.new-features.windows-apache">
    <title>Apache 2.4 handler supported on Windows</title>
 
diff --git a/reference/spl/functions/iterator-to-array.xml b/reference/spl/functions/iterator-to-array.xml
index 670da442d9..ad905ba61b 100644
--- a/reference/spl/functions/iterator-to-array.xml
+++ b/reference/spl/functions/iterator-to-array.xml
@@ -36,6 +36,15 @@
       <para>
        Whether to use the iterator element keys as index.
       </para>
+      <para>
+       In PHP 5.5 and later, if a key is an <type>array</type> or
+       <type>object</type>, a warning will be generated. &null; keys will be
+       converted to an empty string, <type>double</type> keys will be
+       truncated to their <type>integer</type> counterpart,
+       <type>resource</type> keys will generate a warning and be converted to
+       their resource ID, and <type>boolean</type> keys will be converted to
+       integers.
+      </para>
      </listitem>
     </varlistentry>
    </variablelist>
@@ -61,6 +70,14 @@
       </row>
      </thead>
      <tbody>
+      <row>
+       <entry>5.5.0</entry>
+       <entry>
+        <function>iterator_to_array</function> gained support for key types
+        other than <type>integer</type> and <type>string</type> when the
+        <parameter>use_keys</parameter> parameter is enabled.
+       </entry>
+      </row>
       <row>
        <entry>5.2.1</entry>
        <entry>