diff --git a/src/internet/model/ipv4-l3-protocol.cc b/src/internet/model/ipv4-l3-protocol.cc
index 979f0ce34..396fc3a81 100644
--- a/src/internet/model/ipv4-l3-protocol.cc
+++ b/src/internet/model/ipv4-l3-protocol.cc
@@ -532,6 +532,10 @@ Ipv4L3Protocol::SendWithHeader (Ptr<Packet> packet,
                                 Ptr<Ipv4Route> route)
 {
   NS_LOG_FUNCTION (this << packet << ipHeader << route);
+  if (Node::ChecksumEnabled ())
+    {
+      ipHeader.EnableChecksum ();
+    }
   SendRealOut (route, packet, ipHeader);
 }