diff --git a/src/traffic-control/doc/red.rst b/src/traffic-control/doc/red.rst
index d066c937d..1c41a0498 100644
--- a/src/traffic-control/doc/red.rst
+++ b/src/traffic-control/doc/red.rst
@@ -182,7 +182,7 @@ as shown below:
 
 .. sourcecode:: cpp
 
-Config::SetDefault ("ns3::RedQueueDisc::NLRED", BooleanValue (true));
+  Config::SetDefault ("ns3::RedQueueDisc::NLRED", BooleanValue (true));
 
 Examples
 ========