//          http://www.boost.org/LICENSE_1_0.txt)
 #include "icmp/icmpdestinationunreachablemessage.h"
 
+#include <cstddef>
+
 using namespace std;
 
 //-----------------------------------------------------------------------------
 // IcmpDestinationUnreachableMessage
 //-----------------------------------------------------------------------------
 
-static const int MessageSizeInBytes = 44;
+static const size_t MessageSizeInBytes = 44;
 
 IcmpDestinationUnreachableMessage::IcmpDestinationUnreachableMessage() :
     Payload( MessageSizeInBytes )
 
 //          http://www.boost.org/LICENSE_1_0.txt)
 #include "icmp/icmpechoreplymessage.h"
 
+#include <cstddef>
+
 using namespace std;
 
 //-----------------------------------------------------------------------------
 // IcmpEchoReplyMessage
 //-----------------------------------------------------------------------------
 
-static const int MessageSizeInBytes = 8;
+static const size_t MessageSizeInBytes = 8;
 
 IcmpEchoReplyMessage::IcmpEchoReplyMessage() :
     Payload( MessageSizeInBytes )
 
 //          http://www.boost.org/LICENSE_1_0.txt)
 #include "icmp/icmpechorequestmessage.h"
 
+#include <cstddef>
+
 using namespace std;
 
 //-----------------------------------------------------------------------------
 // IcmpEchoRequestMessage
 //-----------------------------------------------------------------------------
 
-static const int MessageSizeInBytes = 8;
+static const size_t MessageSizeInBytes = 8;
 
 IcmpEchoRequestMessage::IcmpEchoRequestMessage() :
     Payload( MessageSizeInBytes )