diff --git a/reference/pdo/pdo/setattribute.xml b/reference/pdo/pdo/setattribute.xml
index 0739a74230..7ea47a743c 100644
--- a/reference/pdo/pdo/setattribute.xml
+++ b/reference/pdo/pdo/setattribute.xml
@@ -66,6 +66,13 @@
      Cannot be used with persistent PDO instances.
      Requires <literal>array(string classname, array(mixed constructor_args))</literal>.
     </para></listitem>
+    <listitem><para><literal>PDO::ATTR_TIMEOUT</literal>:
+     Specifies the timeout duration in seconds.  Not all drivers support this option,
+     and it's meaning may differ from driver to driver.  For example, sqlite will wait
+     for up to this time value before giving up on obtaining an writable lock, but
+     other drivers may interpret this as a connect or a read timeout interval.
+     Requires <type>int</type>.
+    </para></listitem>
     <listitem><para><literal>PDO::ATTR_AUTOCOMMIT</literal>
      (available in OCI, Firebird and MySQL):
      Whether to autocommit every single statement.