diff --git a/openair2/F1AP/f1ap_cu_ue_context_management.c b/openair2/F1AP/f1ap_cu_ue_context_management.c
index 78e0ba02e9..65c34a10c1 100644
--- a/openair2/F1AP/f1ap_cu_ue_context_management.c
+++ b/openair2/F1AP/f1ap_cu_ue_context_management.c
@@ -108,8 +108,12 @@ static void f1ap_write_drb_nssai(const nssai_t *nssai, F1AP_SNSSAI_t *asn1_nssai
   OCTET_STRING_fromBuf(&asn1_nssai->sST, (char *)&nssai->sst, 1);
 
   /* OPTIONAL */
-  if (nssai->sd != 0xffffff)
-    OCTET_STRING_fromBuf(asn1_nssai->sD, (char *)&nssai->sd, 3);
+  if (nssai->sd != 0xffffff) {
+    char sd_buffer[3];
+    INT24_TO_BUFFER(nssai->sd, sd_buffer);
+    asn1cCalloc(asn1_nssai->sD, sD);
+    OCTET_STRING_fromBuf(sD, sd_buffer, 3);
+  }
 }
 
 static void f1ap_write_flows_mapped(const f1ap_flows_mapped_to_drb_t *flows_mapped, F1AP_Flows_Mapped_To_DRB_List_t *asn1_flows_mapped, int n)
diff --git a/openair2/F1AP/f1ap_du_ue_context_management.c b/openair2/F1AP/f1ap_du_ue_context_management.c
index 529c478ac2..ad728d5c89 100644
--- a/openair2/F1AP/f1ap_du_ue_context_management.c
+++ b/openair2/F1AP/f1ap_du_ue_context_management.c
@@ -111,8 +111,9 @@ static void f1ap_read_drb_nssai(const F1AP_SNSSAI_t *asn1_nssai, nssai_t *nssai)
 {
   OCTET_STRING_TO_INT8(&asn1_nssai->sST, nssai->sst);
   nssai->sd = 0xffffff;
-  if (asn1_nssai->sD != NULL)
-    memcpy((uint8_t *)&nssai->sd, asn1_nssai->sD->buf, 3);
+  if (asn1_nssai->sD != NULL) {
+    BUFFER_TO_INT24(asn1_nssai->sD->buf, nssai->sd);
+  }
 }
 
 int DU_handle_UE_CONTEXT_SETUP_REQUEST(instance_t instance, sctp_assoc_t assoc_id, uint32_t stream, F1AP_F1AP_PDU_t *pdu)