diff --git a/lib/src/upper/gtpu.cc b/lib/src/upper/gtpu.cc
index c0a309ed6..729ceac0c 100644
--- a/lib/src/upper/gtpu.cc
+++ b/lib/src/upper/gtpu.cc
@@ -132,7 +132,7 @@ bool gtpu_read_header(srslte::byte_buffer_t* pdu, gtpu_header_t* header, srslte:
     header->next_ext_hdr_type = *ptr;
     ptr++;
 
-    if ((header->flags & GTPU_FLAGS_EXTENDED_HDR) && (header->next_ext_hdr_type == 0b11000000)) {
+    if ((header->flags & GTPU_FLAGS_EXTENDED_HDR) && (header->next_ext_hdr_type == GTPU_EXT_HEADER_PDCP_PDU_NUMBER)) {
       header->ext_buffer.resize(4);
       for (size_t i = 0; i < 4; ++i) {
         header->ext_buffer[i] = *ptr;
diff --git a/srsenb/src/stack/upper/gtpu.cc b/srsenb/src/stack/upper/gtpu.cc
index c4ebf39b6..22f66d186 100644
--- a/srsenb/src/stack/upper/gtpu.cc
+++ b/srsenb/src/stack/upper/gtpu.cc
@@ -128,7 +128,7 @@ void gtpu::send_pdu_to_tunnel(uint16_t                     rnti,
 
   if (pdcp_sn >= 0) {
     header.flags |= GTPU_FLAGS_EXTENDED_HDR;
-    header.next_ext_hdr_type = 0b11000000;
+    header.next_ext_hdr_type = GTPU_EXT_HEADER_PDCP_PDU_NUMBER;
     header.ext_buffer.resize(4u);
     header.ext_buffer[0] = 0x01u;
     header.ext_buffer[1] = (pdcp_sn >> 8u) & 0xffu;