diff --git a/src/mme/mme-gn-build.c b/src/mme/mme-gn-build.c
index 50727f9d0..85d7cb563 100644
--- a/src/mme/mme-gn-build.c
+++ b/src/mme/mme-gn-build.c
@@ -78,6 +78,9 @@ static void build_qos_profile_from_session(ogs_gtp1_qos_profile_decoded_t *qos_p
 
     qos_pdec->qos_profile.data.delivery_erroneous_sdu = OGS_GTP1_DELIVERY_ERR_SDU_NO;
 
+    /* Maximum SDU Size: Encode it as 1500, the maximum for IP 3GPP TS 23.107 Table 4, Note 4) */
+    qos_pdec->qos_profile.data.max_sdu_size = 0x96;
+
      /* 3GPP TS 23.401 Annex E table Table E.3 */
     /* Also take into account table 7 in 3GPP TS 23.107 9.1.2.2 */
     switch (session->qos.index) { /* QCI */
diff --git a/src/smf/gn-build.c b/src/smf/gn-build.c
index 2cc557b1c..d8be2e564 100644
--- a/src/smf/gn-build.c
+++ b/src/smf/gn-build.c
@@ -41,6 +41,14 @@ static void build_qos_profile_from_session(ogs_gtp1_qos_profile_decoded_t *qos_p
 
     qos_pdec->qos_profile.data.delivery_erroneous_sdu = OGS_GTP1_DELIVERY_ERR_SDU_NO;
 
+    /* Maximum SDU Size: If value is set to a valid value, reuse it: */
+    if (sess->gtp.v1.qos_pdec.qos_profile.data.max_sdu_size >= 0x01 &&
+        sess->gtp.v1.qos_pdec.qos_profile.data.max_sdu_size <= 0x99) {
+        qos_pdec->qos_profile.data.max_sdu_size = sess->gtp.v1.qos_pdec.qos_profile.data.max_sdu_size;
+    } else { /* Encode it as 1500, the maximum for IP 3GPP TS 23.107 Table 4, Note 4) */
+        qos_pdec->qos_profile.data.max_sdu_size = 0x96;
+    }
+
      /* 3GPP TS 23.401 Annex E table Table E.3 */
     /* Also take into account table 7 in 3GPP TS 23.107 9.1.2.2 */
     switch (sess->session.qos.index) { /* QCI */