diff --git a/src/internet/model/ipv6-l3-protocol.cc b/src/internet/model/ipv6-l3-protocol.cc
index 449d1911a..8d85045fe 100644
--- a/src/internet/model/ipv6-l3-protocol.cc
+++ b/src/internet/model/ipv6-l3-protocol.cc
@@ -225,15 +225,10 @@ uint32_t Ipv6L3Protocol::AddIpv6Interface (Ptr<Ipv6Interface> interface)
 Ptr<Ipv6Interface> Ipv6L3Protocol::GetInterface (uint32_t index) const
 {
   NS_LOG_FUNCTION (this << index);
-  uint32_t tmp = 0;
 
-  for (Ipv6InterfaceList::const_iterator it = m_interfaces.begin (); it != m_interfaces.end (); it++)
+  if (index < m_interfaces.size ())
     {
-      if (index == tmp)
-        {
-          return *it;
-        }
-      tmp++;
+      return m_interfaces[index];
     }
   return 0;
 }