diff --git a/docs/traffic_shaping.xml b/docs/traffic_shaping.xml
index 6935c8961..be79ace83 100644
--- a/docs/traffic_shaping.xml
+++ b/docs/traffic_shaping.xml
@@ -299,6 +299,11 @@
       </listitem>
     </itemizedlist>
 
+    <warning>
+      <para>Shorewall's builtin traffic shaping feature is limited to ten (10)
+      devices.</para>
+    </warning>
+
     <para>Those few features are really all that builtin traffic
     shaping/control provides; consequently, you need to understand HTB and
     Linux traffic shaping as well as Netfilter packet marking in order to use