diff --git a/src/internet-stack/arp-cache.cc b/src/internet-stack/arp-cache.cc
index b56f05fb8..a3a272bf3 100644
--- a/src/internet-stack/arp-cache.cc
+++ b/src/internet-stack/arp-cache.cc
@@ -33,6 +33,8 @@ NS_LOG_COMPONENT_DEFINE ("ArpCache");
 
 namespace ns3 {
 
+NS_OBJECT_ENSURE_REGISTERED (ArpCache);
+
 TypeId 
 ArpCache::GetTypeId (void)
 {