diff --git a/doc/source/dce-user-kernel.rst b/doc/source/dce-user-kernel.rst
index 002d259a..d602ceb3 100644
--- a/doc/source/dce-user-kernel.rst
+++ b/doc/source/dce-user-kernel.rst
@@ -98,6 +98,12 @@ The next step would be writing |ns3| simulation scenario to use the applications
    apps = process.Install (nodes.Get (1));
    apps.Start (Seconds (1.5));
 
+**Optional**
+When running hybrid simulations, i.e. with both kernel and ns3 stacks, the kernel will drop packets with invalid checksums. You can enable ns3 checksums globally:
+
+  1. if you pass the argument '--ChecksumEnabled=1' to any program that includes CommandLine parsing.
+  2. if you export the environment variable NS_GLOBAL_VALUE="ChecksumEnabled=1" before launching your simulation
+
 5. run it !
 --------