diff --git a/tools/socktap/tcp_link.cpp b/tools/socktap/tcp_link.cpp
index 0d3c0532a..2323795a8 100644
--- a/tools/socktap/tcp_link.cpp
+++ b/tools/socktap/tcp_link.cpp
@@ -30,7 +30,7 @@ void TcpLink::request(const access::DataRequest& request, std::unique_ptr<ChunkP
     vanetza::ByteBuffer buffer = create_ethernet_header(request.destination_addr, request.source_addr, request.ether_type);
 
     // insert packet size before ethernet header
-    uint16_t packet_size = packet->size() + EthernetHeader::length_bytes;
+    uint16_t packet_size = packet->size(OsiLayer::Network, OsiLayer::Application) + EthernetHeader::length_bytes;
     buffer.insert(buffer.begin(), packet_size & 0x00FF);
     buffer.insert(buffer.begin(), (packet_size & 0xFF00) >> 8);