diff --git a/openair2/GNB_APP/gnb_config.c b/openair2/GNB_APP/gnb_config.c
index dfbe4c3672..a0db5ad338 100644
--- a/openair2/GNB_APP/gnb_config.c
+++ b/openair2/GNB_APP/gnb_config.c
@@ -1181,7 +1181,8 @@ static f1ap_setup_req_t *RC_read_F1Setup(uint64_t id,
     sys_info->mib = calloc(buf_len, sizeof(*sys_info->mib));
     DevAssert(sys_info->mib != NULL);
     DevAssert(mib != NULL);
-    sys_info->mib_length = encode_MIB_NR(mib, 0, sys_info->mib, buf_len);
+    // encode only the mib message itself
+    sys_info->mib_length = encode_MIB_NR_setup(mib->message.choice.mib, 0, sys_info->mib, buf_len);
     DevAssert(sys_info->mib_length == buf_len);
 
     DevAssert(sib1 != NULL);
diff --git a/openair2/RRC/NR/nr_rrc_config.c b/openair2/RRC/NR/nr_rrc_config.c
index b6a5d45ff9..be1aaeec82 100644
--- a/openair2/RRC/NR/nr_rrc_config.c
+++ b/openair2/RRC/NR/nr_rrc_config.c
@@ -1875,6 +1875,18 @@ int encode_MIB_NR(NR_BCCH_BCH_Message_t *mib, int frame, uint8_t *buf, int buf_s
   return (enc_rval.encoded + 7) / 8;
 }
 
+int encode_MIB_NR_setup(NR_MIB_t *mib, int frame, uint8_t *buf, int buf_size)
+{
+  DevAssert(mib != NULL);
+  uint8_t sfn_msb = (uint8_t)((frame >> 4) & 0x3f);
+  *mib->systemFrameNumber.buf = sfn_msb << 2;
+
+  asn_enc_rval_t enc_rval = uper_encode_to_buffer(&asn_DEF_NR_MIB, NULL, mib, buf, buf_size);
+  AssertFatal(enc_rval.encoded > 0, "ASN1 message encoding failed (%s, %lu)!\n", enc_rval.failed_type->name, enc_rval.encoded);
+  LOG_D(NR_RRC, "Encoded MIB for frame %d sfn_msb %d, bits %lu\n", frame, sfn_msb, enc_rval.encoded);
+  return (enc_rval.encoded + 7) / 8;
+}
+
 NR_BCCH_DL_SCH_Message_t *get_SIB1_NR(const NR_ServingCellConfigCommon_t *scc, const f1ap_plmn_t *plmn, uint64_t cellID, int tac)
 {
   AssertFatal(cellID < (1l << 36), "cellID must fit within 36 bits, but is %lu\n", cellID);
diff --git a/openair2/RRC/NR/nr_rrc_config.h b/openair2/RRC/NR/nr_rrc_config.h
index 1db2d4a2f1..b18be2ff61 100644
--- a/openair2/RRC/NR/nr_rrc_config.h
+++ b/openair2/RRC/NR/nr_rrc_config.h
@@ -55,6 +55,7 @@ void prepare_sim_uecap(NR_UE_NR_Capability_t *cap,
 NR_BCCH_BCH_Message_t *get_new_MIB_NR(const NR_ServingCellConfigCommon_t *scc);
 void free_MIB_NR(NR_BCCH_BCH_Message_t *mib);
 int encode_MIB_NR(NR_BCCH_BCH_Message_t *mib, int frame, uint8_t *buf, int buf_size);
+int encode_MIB_NR_setup(NR_MIB_t *mib, int frame, uint8_t *buf, int buf_size);
 
 
 #define NR_MAX_SIB_LENGTH 2976 // 3GPP TS 38.331 section 5.2.1
diff --git a/openair2/RRC/NR/rrc_gNB_du.c b/openair2/RRC/NR/rrc_gNB_du.c
index fdbe1a4551..c67263a67e 100644
--- a/openair2/RRC/NR/rrc_gNB_du.c
+++ b/openair2/RRC/NR/rrc_gNB_du.c
@@ -49,35 +49,33 @@ static bool rrc_gNB_plmn_matches(const gNB_RRC_INST *rrc, const f1ap_served_cell
     && conf->mnc[0] == info->plmn.mnc;
 }
 
-static bool extract_sys_info(const f1ap_gnb_du_system_info_t *sys_info, NR_BCCH_BCH_Message_t **mib, NR_SIB1_t **sib1)
+static bool extract_sys_info(const f1ap_gnb_du_system_info_t *sys_info, NR_MIB_t **mib, NR_SIB1_t **sib1)
 {
   DevAssert(sys_info != NULL);
   DevAssert(mib != NULL);
   DevAssert(sib1 != NULL);
 
-  asn_dec_rval_t dec_rval =
-      uper_decode_complete(NULL, &asn_DEF_NR_BCCH_BCH_Message, (void **)mib, sys_info->mib, sys_info->mib_length);
-  if (dec_rval.code != RC_OK || (*mib)->message.present != NR_BCCH_BCH_MessageType_PR_mib
-      || (*mib)->message.choice.messageClassExtension == NULL) {
-    LOG_E(RRC, "Failed to decode NR_BCCH_BCH_MESSAGE (%zu bits) of DU\n", dec_rval.consumed);
-    ASN_STRUCT_FREE(asn_DEF_NR_BCCH_BCH_Message, *mib);
+  asn_dec_rval_t dec_rval = uper_decode_complete(NULL, &asn_DEF_NR_MIB, (void **)mib, sys_info->mib, sys_info->mib_length);
+  if (dec_rval.code != RC_OK) {
+    LOG_E(RRC, "Failed to decode NR_MIB (%zu bits) of DU\n", dec_rval.consumed);
+    ASN_STRUCT_FREE(asn_DEF_NR_MIB, *mib);
     return false;
   }
 
   if (sys_info->sib1) {
     dec_rval = uper_decode_complete(NULL, &asn_DEF_NR_SIB1, (void **)sib1, sys_info->sib1, sys_info->sib1_length);
     if (dec_rval.code != RC_OK) {
-      ASN_STRUCT_FREE(asn_DEF_NR_BCCH_BCH_Message, *mib);
+      ASN_STRUCT_FREE(asn_DEF_NR_MIB, *mib);
       ASN_STRUCT_FREE(asn_DEF_NR_SIB1, *sib1);
       LOG_E(RRC, "Failed to decode NR_SIB1 (%zu bits), rejecting DU\n", dec_rval.consumed);
       return false;
     }
   }
 
-  if (LOG_DEBUGFLAG(DEBUG_ASN1))
-    xer_fprint(stdout, &asn_DEF_NR_BCCH_BCH_Message, *mib);
-  if (LOG_DEBUGFLAG(DEBUG_ASN1))
+  if (LOG_DEBUGFLAG(DEBUG_ASN1)) {
+    xer_fprint(stdout, &asn_DEF_NR_MIB, *mib);
     xer_fprint(stdout, &asn_DEF_NR_SIB1, *sib1);
+  }
 
   return true;
 }
@@ -145,7 +143,7 @@ void rrc_gNB_process_f1_setup_req(f1ap_setup_req_t *req, sctp_assoc_t assoc_id)
   }
 
   const f1ap_gnb_du_system_info_t *sys_info = req->cell[0].sys_info;
-  NR_BCCH_BCH_Message_t *mib = NULL;
+  NR_MIB_t *mib = NULL;
   NR_SIB1_t *sib1 = NULL;
 
   if (sys_info != NULL && sys_info->mib != NULL && !(sys_info->sib1 == NULL && get_softmodem_params()->sa)) {
@@ -170,12 +168,9 @@ void rrc_gNB_process_f1_setup_req(f1ap_setup_req_t *req, sctp_assoc_t assoc_id)
   du->setup_req = calloc(1,sizeof(*du->setup_req));
   AssertFatal(du->setup_req, "out of memory\n");
   *du->setup_req = *req;
-  if (mib != NULL && sib1 != NULL) {
-    du->mib = mib->message.choice.mib;
-    mib->message.choice.mib = NULL;
-    ASN_STRUCT_FREE(asn_DEF_NR_BCCH_BCH_MessageType, mib);
-    du->sib1 = sib1;
-  }
+  // MIB can be null and configured later via DU Configuration Update
+  du->mib = mib;
+  du->sib1 = sib1;
   RB_INSERT(rrc_du_tree, &rrc->dus, du);
   rrc->num_dus++;
 
@@ -184,7 +179,7 @@ void rrc_gNB_process_f1_setup_req(f1ap_setup_req_t *req, sctp_assoc_t assoc_id)
       .nr_cellid = cell_info->nr_cellid,
       .nrpci = cell_info->nr_pci,
       .num_SI = 0,
-  };  
+  };
 
   f1ap_setup_resp_t resp = {.transaction_id = req->transaction_id,
                             .num_cells_to_activate = 1,
@@ -288,14 +283,12 @@ void rrc_gNB_process_f1_du_configuration_update(f1ap_gnb_du_configuration_update
       if (sys_info->sib1 != NULL)
         ASN_STRUCT_FREE(asn_DEF_NR_SIB1, du->sib1);
 
-      NR_BCCH_BCH_Message_t *mib = NULL;
+      NR_MIB_t *mib = NULL;
       if (!extract_sys_info(sys_info, &mib, &du->sib1)) {
         LOG_W(RRC, "cannot update sys_info for DU %ld\n", du->setup_req->gNB_DU_id);
       } else {
         DevAssert(mib != NULL);
-        du->mib = mib->message.choice.mib;
-        mib->message.choice.mib = NULL;
-        ASN_STRUCT_FREE(asn_DEF_NR_BCCH_BCH_MessageType, mib);
+        du->mib = mib;
         LOG_I(RRC, "update system information of DU %ld\n", du->setup_req->gNB_DU_id);
       }
     }