diff --git a/reference/curl/constants.xml b/reference/curl/constants.xml
index 631dfd0d21..84990427ee 100644
--- a/reference/curl/constants.xml
+++ b/reference/curl/constants.xml
@@ -2874,6 +2874,28 @@
     </simpara>
    </listitem>
   </varlistentry>
+  <varlistentry xml:id="constant.curlproxy-socks4a">
+   <term>
+    <constant>CURLPROXY_SOCKS4A</constant>
+    (<type>integer</type>)
+   </term>
+   <listitem>
+    <simpara>
+     Available since PHP 5.5.23 and PHP 5.6.7 and cURL 7.18.0.
+    </simpara>
+   </listitem>
+  </varlistentry>
+  <varlistentry xml:id="constant.curlproxy-socks5-hostname">
+   <term>
+    <constant>CURLPROXY_SOCKS5_HOSTNAME</constant>
+    (<type>integer</type>)
+   </term>
+   <listitem>
+    <simpara>
+     Available since PHP 5.5.23 and PHP 5.6.7 and cURL 7.18.0.
+    </simpara>
+   </listitem>
+  </varlistentry>
  </variablelist>
 
 </appendix>