diff --git a/reference/mongo/mongo/getslave.xml b/reference/mongo/mongo/getslave.xml
index d2150d9f42..ceccdd623e 100644
--- a/reference/mongo/mongo/getslave.xml
+++ b/reference/mongo/mongo/getslave.xml
@@ -20,6 +20,14 @@
    object.
   </para>
 
+  <para>
+   When you create a connection to the database, the driver will not immediately
+   decide on a slave to use.  Thus, after you connect, this function will return
+   &null; even if there are slaves available. When you first do a query with
+   slaveOkay set, at that point the driver will choose a slave for this
+   connection.  At that point, this function will return the chosen slave.
+  </para>
+
   <para>
    See <link linkend="mongo.queries">the query section</link> of this manual for
    information on distributing reads to slaves.
@@ -62,4 +70,4 @@ End:
 vim600: syn=xml fen fdm=syntax fdl=2 si
 vim: et tw=78 syn=sgml
 vi: ts=1 sw=1
---> 
+-->
diff --git a/reference/mongo/queries.xml b/reference/mongo/queries.xml
index 018c3f4cce..ba32caed79 100644
--- a/reference/mongo/queries.xml
+++ b/reference/mongo/queries.xml
@@ -64,10 +64,12 @@ $cursor = $c->find();
 
 // on the Australian client
 $m1 = new Mongo("mongodb://P", array("replicaSet" => true));
+$m1->foo->bar->find()->slaveOkay()->getNext();
 echo "m1's slave is ".$m1->getSlave()."\n";
 
 // on the European client
 $m2 = new Mongo("mongodb://P", array("replicaSet" => true));
+$m2->foo->bar->find()->slaveOkay()->getNext();
 echo "m2's slave is ".$m2->getSlave()."\n";
 
 ?>
@@ -81,6 +83,12 @@ m1's slave is: australianHost
 m2's slave is: europeanHost
    </screen>
 
+   <para>
+    Note that we have to do a query before a slave is chosen: slaves are chosen
+    lazily by the driver.  <function>Mongo::getSlave</function> will return
+    &null; until a slave is used.
+   </para>
+
    <para>
     You can see what the driver thinks is the current status of the set members
     by running <function>Mongo::getHosts</function>.