diff --git a/doc/NO_SYS_SampleCode.c b/doc/NO_SYS_SampleCode.c
index a8dc377b..f20106f5 100644
--- a/doc/NO_SYS_SampleCode.c
+++ b/doc/NO_SYS_SampleCode.c
@@ -54,7 +54,7 @@ static err_t netif_init(struct netif *netif)
   netif->flags = NETIF_FLAG_BROADCAST | NETIF_FLAG_ETHARP | NETIF_FLAG_ETHERNET | NETIF_FLAG_IGMP;
   MIB2_INIT_NETIF(netif, snmp_ifType_ethernet_csmacd, 100000000);
 
-  memcpy(netif->hwaddr, your_mac_address_goes_here, sizeof(netif->hwaddr));
+  SMEMCPY(netif->hwaddr, your_mac_address_goes_here, sizeof(netif->hwaddr));
   netif->hwaddr_len = sizeof(netif->hwaddr);
 
   return ERR_OK;
diff --git a/src/api/sockets.c b/src/api/sockets.c
index 68ff0a51..620e4849 100644
--- a/src/api/sockets.c
+++ b/src/api/sockets.c
@@ -1829,7 +1829,7 @@ lwip_getsockopt(int s, int level, int optname, void *optval, socklen_t *optlen)
   /* write back optlen and optval */
   *optlen = LWIP_SETGETSOCKOPT_DATA_VAR_REF(data).optlen;
 #if LWIP_MPU_COMPATIBLE
-  memcpy(optval, LWIP_SETGETSOCKOPT_DATA_VAR_REF(data).optval,
+  MEMCPY(optval, LWIP_SETGETSOCKOPT_DATA_VAR_REF(data).optval,
     LWIP_SETGETSOCKOPT_DATA_VAR_REF(data).optlen);
 #endif /* LWIP_MPU_COMPATIBLE */
 
@@ -2217,7 +2217,7 @@ lwip_setsockopt(int s, int level, int optname, const void *optval, socklen_t opt
   LWIP_SETGETSOCKOPT_DATA_VAR_REF(data).optname = optname;
   LWIP_SETGETSOCKOPT_DATA_VAR_REF(data).optlen = optlen;
 #if LWIP_MPU_COMPATIBLE
-  memcpy(LWIP_SETGETSOCKOPT_DATA_VAR_REF(data).optval, optval, optlen);
+  MEMCPY(LWIP_SETGETSOCKOPT_DATA_VAR_REF(data).optval, optval, optlen);
 #else /* LWIP_MPU_COMPATIBLE */
   LWIP_SETGETSOCKOPT_DATA_VAR_REF(data).optval.pc = (const void*)optval;
 #endif /* LWIP_MPU_COMPATIBLE */
diff --git a/src/apps/lwiperf/lwiperf.c b/src/apps/lwiperf/lwiperf.c
index 1682f358..fea2c06f 100644
--- a/src/apps/lwiperf/lwiperf.c
+++ b/src/apps/lwiperf/lwiperf.c
@@ -374,7 +374,7 @@ lwiperf_tx_start(lwiperf_state_tcp_t* conn)
     return ERR_MEM;
   }
 
-  memcpy(client_conn, conn, sizeof(lwiperf_state_tcp_t));
+  MEMCPY(client_conn, conn, sizeof(lwiperf_state_tcp_t));
   client_conn->base.server = 0;
   client_conn->server_pcb = NULL;
   client_conn->conn_pcb = newpcb;
diff --git a/src/apps/mdns/mdns.c b/src/apps/mdns/mdns.c
index 4cf32ea1..6fc7ce7f 100644
--- a/src/apps/mdns/mdns.c
+++ b/src/apps/mdns/mdns.c
@@ -322,7 +322,7 @@ mdns_domain_add_label(struct mdns_domain *domain, const char *label, u8_t len)
   domain->name[domain->length] = len;
   domain->length++;
   if (len) {
-    memcpy(&domain->name[domain->length], label, len);
+    MEMCPY(&domain->name[domain->length], label, len);
     domain->length += len;
   }
   return ERR_OK;
@@ -1256,7 +1256,7 @@ mdns_init_outpacket(struct mdns_outpacket *out, struct mdns_packet *in)
   /* Copy source IP/port to use when responding unicast, or to choose
    * which pcb to use for multicast (IPv4/IPv6)
    */
-  memcpy(&out->dest_addr, &in->source_addr, sizeof(ip_addr_t));
+  SMEMCPY(&out->dest_addr, &in->source_addr, sizeof(ip_addr_t));
   out->dest_port = in->source_port;
 
   if (in->source_port != MDNS_PORT) {
@@ -1509,7 +1509,7 @@ mdns_announce(struct netif *netif, const ip_addr_t *destination)
   }
 
   announce.dest_port = MDNS_PORT;
-  memcpy(&announce.dest_addr, destination, sizeof(announce.dest_addr));
+  SMEMCPY(&announce.dest_addr, destination, sizeof(announce.dest_addr));
   mdns_send_outpacket(&announce);
 }
 
@@ -1800,7 +1800,7 @@ mdns_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, const ip_addr_t *addr,
   }
 
   memset(&packet, 0, sizeof(packet));
-  memcpy(&packet.source_addr, addr, sizeof(packet.source_addr));
+  SMEMCPY(&packet.source_addr, addr, sizeof(packet.source_addr));
   packet.source_port = port;
   packet.netif = recv_netif;
   packet.pbuf = p;
@@ -1909,7 +1909,7 @@ mdns_resp_add_netif(struct netif *netif, const char *hostname, u32_t dns_ttl)
   netif->client_data[mdns_netif_client_id] = mdns;
 
   memset(mdns, 0, sizeof(struct mdns_host));
-  memcpy(&mdns->name, hostname, LWIP_MIN(MDNS_LABEL_MAXLEN, strlen(hostname)));
+  MEMCPY(&mdns->name, hostname, LWIP_MIN(MDNS_LABEL_MAXLEN, strlen(hostname)));
   mdns->dns_ttl = dns_ttl;
 
   /* Join multicast groups */
@@ -2016,8 +2016,8 @@ mdns_resp_add_service(struct netif *netif, const char *name, const char *service
 
   memset(srv, 0, sizeof(struct mdns_service));
 
-  memcpy(&srv->name, name, LWIP_MIN(MDNS_LABEL_MAXLEN, strlen(name)));
-  memcpy(&srv->service, service, LWIP_MIN(MDNS_LABEL_MAXLEN, strlen(service)));
+  MEMCPY(&srv->name, name, LWIP_MIN(MDNS_LABEL_MAXLEN, strlen(name)));
+  MEMCPY(&srv->service, service, LWIP_MIN(MDNS_LABEL_MAXLEN, strlen(service)));
   srv->txt_fn = txt_fn;
   srv->txt_userdata = txt_data;
   srv->proto = (u16_t)proto;
diff --git a/src/apps/netbiosns/netbiosns.c b/src/apps/netbiosns/netbiosns.c
index dd01c026..1b1f952e 100644
--- a/src/apps/netbiosns/netbiosns.c
+++ b/src/apps/netbiosns/netbiosns.c
@@ -346,7 +346,7 @@ netbiosns_set_name(const char* hostname)
   if (copy_len >= NETBIOS_NAME_LEN) {
     copy_len = NETBIOS_NAME_LEN - 1;
   }
-  memcpy(netbiosns_local_name, hostname, copy_len + 1);
+  MEMCPY(netbiosns_local_name, hostname, copy_len + 1);
 }
 #endif
 
diff --git a/src/apps/snmp/snmp_msg.c b/src/apps/snmp/snmp_msg.c
index 6a083ad1..b06266f6 100644
--- a/src/apps/snmp/snmp_msg.c
+++ b/src/apps/snmp/snmp_msg.c
@@ -1067,7 +1067,7 @@ snmp_prepare_outbound_frame(struct snmp_request *request)
 
     /* msgAuthoritativeEngineID */
     snmpv3_get_engine_id(&id, &request->msg_authoritative_engine_id_len);
-    memcpy(request->msg_authoritative_engine_id, id, request->msg_authoritative_engine_id_len);
+    MEMCPY(request->msg_authoritative_engine_id, id, request->msg_authoritative_engine_id_len);
     SNMP_ASN1_SET_TLV_PARAMS(tlv, SNMP_ASN1_TYPE_OCTET_STRING, 0, request->msg_authoritative_engine_id_len);
     OF_BUILD_EXEC(snmp_ans1_enc_tlv(pbuf_stream, &tlv));
     OF_BUILD_EXEC(snmp_asn1_enc_raw(pbuf_stream, request->msg_authoritative_engine_id, request->msg_authoritative_engine_id_len));
@@ -1142,7 +1142,7 @@ snmp_prepare_outbound_frame(struct snmp_request *request)
 
     /* contextEngineID */
     snmpv3_get_engine_id(&id, &request->context_engine_id_len);
-    memcpy(request->context_engine_id, id, request->context_engine_id_len);
+    MEMCPY(request->context_engine_id, id, request->context_engine_id_len);
     SNMP_ASN1_SET_TLV_PARAMS(tlv, SNMP_ASN1_TYPE_OCTET_STRING, 0, request->context_engine_id_len);
     OF_BUILD_EXEC(snmp_ans1_enc_tlv(pbuf_stream, &tlv));
     OF_BUILD_EXEC(snmp_asn1_enc_raw(pbuf_stream, request->context_engine_id, request->context_engine_id_len));
@@ -1519,7 +1519,7 @@ snmp_complete_outbound_frame(struct snmp_request *request)
         request->outbound_pbuf, 0, request->outbound_pbuf->tot_len));
     OF_BUILD_EXEC(snmpv3_auth(&request->outbound_pbuf_stream, frame_size + outbound_padding, key, algo, hmac));
 
-    memcpy(request->msg_authentication_parameters, hmac, SNMP_V3_MAX_AUTH_PARAM_LENGTH);
+    MEMCPY(request->msg_authentication_parameters, hmac, SNMP_V3_MAX_AUTH_PARAM_LENGTH);
     OF_BUILD_EXEC(snmp_pbuf_stream_init(&request->outbound_pbuf_stream,
                   request->outbound_pbuf, 0, request->outbound_pbuf->tot_len));
     OF_BUILD_EXEC(snmp_pbuf_stream_seek_abs(&request->outbound_pbuf_stream,
diff --git a/src/apps/snmp/snmpv3.c b/src/apps/snmp/snmpv3.c
index e5dfa321..69fb3a0a 100644
--- a/src/apps/snmp/snmpv3.c
+++ b/src/apps/snmp/snmpv3.c
@@ -114,8 +114,8 @@ snmpv3_build_priv_param(u8_t* priv_param)
     priv2 = LWIP_RAND();
   }
 
-  memcpy(&priv_param[0], &priv1, sizeof(priv1));
-  memcpy(&priv_param[4], &priv2, sizeof(priv2));
+  SMEMCPY(&priv_param[0], &priv1, sizeof(priv1));
+  SMEMCPY(&priv_param[4], &priv2, sizeof(priv2));
 
   /* Emulate 64bit increment */
   priv1++;
@@ -125,8 +125,8 @@ snmpv3_build_priv_param(u8_t* priv_param)
 #else /* Based on RFC3414 */
   static u32_t ctr;
   u32_t boots = LWIP_SNMPV3_GET_ENGINE_BOOTS();
-  memcpy(&priv_param[0], &boots, 4);
-  memcpy(&priv_param[4], &ctr, 4);
+  SMEMCPY(&priv_param[0], &boots, 4);
+  SMEMCPY(&priv_param[4], &ctr, 4);
   ctr++;
 #endif
   return ERR_OK;
diff --git a/src/apps/snmp/snmpv3_mbedtls.c b/src/apps/snmp/snmpv3_mbedtls.c
index 2a0598ba..0b1eefb8 100644
--- a/src/apps/snmp/snmpv3_mbedtls.c
+++ b/src/apps/snmp/snmpv3_mbedtls.c
@@ -192,7 +192,7 @@ snmpv3_crypt(struct snmp_pbuf_stream* stream, u16_t length,
     iv_local[4 + 1] = (engine_time  >> 16) & 0xFF;
     iv_local[4 + 2] = (engine_time  >>  8) & 0xFF;
     iv_local[4 + 3] = (engine_time  >>  0) & 0xFF;
-    memcpy(iv_local + 8, priv_param, 8);
+    SMEMCPY(iv_local + 8, priv_param, 8);
     if(mbedtls_cipher_set_iv(&ctx, iv_local, LWIP_ARRAYSIZE(iv_local)) != 0) {
       goto error;
     }
@@ -263,9 +263,9 @@ snmpv3_password_to_key_md5(
   /* May want to ensure that engineLength <= 32,       */
   /* otherwise need to use a buffer larger than 64     */
   /*****************************************************/
-  memcpy(password_buf, key, 16);
-  memcpy(password_buf + 16, engineID, engineLength);
-  memcpy(password_buf + 16 + engineLength, key, 16);
+  SMEMCPY(password_buf, key, 16);
+  MEMCPY(password_buf + 16, engineID, engineLength);
+  SMEMCPY(password_buf + 16 + engineLength, key, 16);
 
   mbedtls_md5_starts(&MD);
   mbedtls_md5_update(&MD, password_buf, 32 + engineLength);
@@ -316,9 +316,9 @@ snmpv3_password_to_key_sha(
   /* May want to ensure that engineLength <= 32,       */
   /* otherwise need to use a buffer larger than 72     */
   /*****************************************************/
-  memcpy(password_buf, key, 20);
-  memcpy(password_buf + 20, engineID, engineLength);
-  memcpy(password_buf + 20 + engineLength, key, 20);
+  SMEMCPY(password_buf, key, 20);
+  MEMCPY(password_buf + 20, engineID, engineLength);
+  SMEMCPY(password_buf + 20 + engineLength, key, 20);
 
   mbedtls_sha1_starts(&SH);
   mbedtls_sha1_update(&SH, password_buf, 40 + engineLength);