diff --git a/extmod/modnetwork.c b/extmod/modnetwork.c
index 0ff8683b74..d5c8f83ea4 100644
--- a/extmod/modnetwork.c
+++ b/extmod/modnetwork.c
@@ -77,7 +77,7 @@ mp_obj_t mod_network_find_nic(const uint8_t *ip) {
     for (mp_uint_t i = 0; i < MP_STATE_PORT(mod_network_nic_list).len; i++) {
         mp_obj_t nic = MP_STATE_PORT(mod_network_nic_list).items[i];
         // TODO check IP suitability here
-        // mod_network_nic_type_t *nic_type = (mod_network_nic_type_t*)mp_obj_get_type(nic);
+        // mod_network_nic_protocol_t *nic_protocol = (mod_network_nic_protocol_t *)MP_OBJ_TYPE_GET_SLOT(mp_obj_get_type(nic), protocol);
         return nic;
     }
 
diff --git a/extmod/modnetwork.h b/extmod/modnetwork.h
index 55ee4eb4d3..a28ec6e420 100644
--- a/extmod/modnetwork.h
+++ b/extmod/modnetwork.h
@@ -61,10 +61,7 @@ mp_obj_t mod_network_nic_ifconfig(struct netif *netif, size_t n_args, const mp_o
 
 struct _mod_network_socket_obj_t;
 
-typedef struct _mod_network_nic_type_t {
-    // Ensure that this struct is big enough to hold any type size.
-    mp_obj_full_type_t base;
-
+typedef struct _mod_network_nic_protocol_t {
     // API for non-socket operations
     int (*gethostbyname)(mp_obj_t nic, const char *name, mp_uint_t len, uint8_t *ip_out);
 
@@ -82,12 +79,12 @@ typedef struct _mod_network_nic_type_t {
     int (*setsockopt)(struct _mod_network_socket_obj_t *socket, mp_uint_t level, mp_uint_t opt, const void *optval, mp_uint_t optlen, int *_errno);
     int (*settimeout)(struct _mod_network_socket_obj_t *socket, mp_uint_t timeout_ms, int *_errno);
     int (*ioctl)(struct _mod_network_socket_obj_t *socket, mp_uint_t request, mp_uint_t arg, int *_errno);
-} mod_network_nic_type_t;
+} mod_network_nic_protocol_t;
 
 typedef struct _mod_network_socket_obj_t {
     mp_obj_base_t base;
     mp_obj_t nic;
-    mod_network_nic_type_t *nic_type;
+    mod_network_nic_protocol_t *nic_protocol;
     uint32_t domain : 5;
     uint32_t type   : 5;
     uint32_t proto  : 5;
diff --git a/extmod/modusocket.c b/extmod/modusocket.c
index 0006465924..2aa6010884 100644
--- a/extmod/modusocket.c
+++ b/extmod/modusocket.c
@@ -57,7 +57,7 @@ STATIC mp_obj_t socket_make_new(const mp_obj_type_t *type, size_t n_args, size_t
     mod_network_socket_obj_t *s = m_new_obj_with_finaliser(mod_network_socket_obj_t);
     s->base.type = &socket_type;
     s->nic = MP_OBJ_NULL;
-    s->nic_type = NULL;
+    s->nic_protocol = NULL;
     s->domain = MOD_NETWORK_AF_INET;
     s->type = MOD_NETWORK_SOCK_STREAM;
     s->proto = 0;
@@ -86,17 +86,17 @@ STATIC void socket_select_nic(mod_network_socket_obj_t *self, const byte *ip) {
     if (self->nic == MP_OBJ_NULL) {
         // select NIC based on IP
         self->nic = mod_network_find_nic(ip);
-        self->nic_type = (mod_network_nic_type_t *)mp_obj_get_type(self->nic);
+        self->nic_protocol = (mod_network_nic_protocol_t *)MP_OBJ_TYPE_GET_SLOT(mp_obj_get_type(self->nic), protocol);
 
         // call the NIC to open the socket
         int _errno;
-        if (self->nic_type->socket(self, &_errno) != 0) {
+        if (self->nic_protocol->socket(self, &_errno) != 0) {
             mp_raise_OSError(_errno);
         }
 
         #if MICROPY_PY_USOCKET_EXTENDED_STATE
         // if a timeout was set before binding a NIC, call settimeout to reset it
-        if (self->timeout != -1 && self->nic_type->settimeout(self, self->timeout, &_errno) != 0) {
+        if (self->timeout != -1 && self->nic_protocol->settimeout(self, self->timeout, &_errno) != 0) {
             mp_raise_OSError(_errno);
         }
         #endif
@@ -116,7 +116,7 @@ STATIC mp_obj_t socket_bind(mp_obj_t self_in, mp_obj_t addr_in) {
 
     // call the NIC to bind the socket
     int _errno;
-    if (self->nic_type->bind(self, ip, port, &_errno) != 0) {
+    if (self->nic_protocol->bind(self, ip, port, &_errno) != 0) {
         mp_raise_OSError(_errno);
     }
 
@@ -141,7 +141,7 @@ STATIC mp_obj_t socket_listen(size_t n_args, const mp_obj_t *args) {
     }
 
     int _errno;
-    if (self->nic_type->listen(self, backlog, &_errno) != 0) {
+    if (self->nic_protocol->listen(self, backlog, &_errno) != 0) {
         mp_raise_OSError(_errno);
     }
 
@@ -166,7 +166,7 @@ STATIC mp_obj_t socket_accept(mp_obj_t self_in) {
     mod_network_socket_obj_t *socket2 = m_new_obj_with_finaliser(mod_network_socket_obj_t);
     socket2->base.type = &socket_type;
     socket2->nic = MP_OBJ_NULL;
-    socket2->nic_type = NULL;
+    socket2->nic_protocol = NULL;
 
     // set the same address family, socket type and protocol as parent
     socket2->domain = self->domain;
@@ -185,13 +185,13 @@ STATIC mp_obj_t socket_accept(mp_obj_t self_in) {
     uint8_t ip[MOD_NETWORK_IPADDR_BUF_SIZE];
     mp_uint_t port;
     int _errno;
-    if (self->nic_type->accept(self, socket2, ip, &port, &_errno) != 0) {
+    if (self->nic_protocol->accept(self, socket2, ip, &port, &_errno) != 0) {
         mp_raise_OSError(_errno);
     }
 
     // new socket has valid state, so set the NIC to the same as parent
     socket2->nic = self->nic;
-    socket2->nic_type = self->nic_type;
+    socket2->nic_protocol = self->nic_protocol;
 
     // make the return value
     mp_obj_tuple_t *client = MP_OBJ_TO_PTR(mp_obj_new_tuple(2, NULL));
@@ -215,7 +215,7 @@ STATIC mp_obj_t socket_connect(mp_obj_t self_in, mp_obj_t addr_in) {
 
     // call the NIC to connect the socket
     int _errno;
-    if (self->nic_type->connect(self, ip, port, &_errno) != 0) {
+    if (self->nic_protocol->connect(self, ip, port, &_errno) != 0) {
         mp_raise_OSError(_errno);
     }
 
@@ -236,7 +236,7 @@ STATIC mp_obj_t socket_send(mp_obj_t self_in, mp_obj_t buf_in) {
     mp_buffer_info_t bufinfo;
     mp_get_buffer_raise(buf_in, &bufinfo, MP_BUFFER_READ);
     int _errno;
-    mp_uint_t ret = self->nic_type->send(self, bufinfo.buf, bufinfo.len, &_errno);
+    mp_uint_t ret = self->nic_protocol->send(self, bufinfo.buf, bufinfo.len, &_errno);
     if (ret == -1) {
         mp_raise_OSError(_errno);
     }
@@ -256,7 +256,7 @@ STATIC mp_obj_t socket_sendall(mp_obj_t self_in, mp_obj_t buf_in) {
     int _errno;
     mp_uint_t ret = 0;
     if (self->timeout == 0) {
-        ret = self->nic_type->send(self, bufinfo.buf, bufinfo.len, &_errno);
+        ret = self->nic_protocol->send(self, bufinfo.buf, bufinfo.len, &_errno);
         if (ret == -1) {
             mp_raise_OSError(_errno);
         } else if (bufinfo.len > ret) {
@@ -266,7 +266,7 @@ STATIC mp_obj_t socket_sendall(mp_obj_t self_in, mp_obj_t buf_in) {
         // TODO: In CPython3.5, socket timeout should apply to the
         // entire sendall() operation, not to individual send() chunks.
         while (bufinfo.len != 0) {
-            ret = self->nic_type->send(self, bufinfo.buf, bufinfo.len, &_errno);
+            ret = self->nic_protocol->send(self, bufinfo.buf, bufinfo.len, &_errno);
             if (ret == -1) {
                 mp_raise_OSError(_errno);
             }
@@ -289,7 +289,7 @@ STATIC mp_obj_t socket_recv(mp_obj_t self_in, mp_obj_t len_in) {
     vstr_t vstr;
     vstr_init_len(&vstr, len);
     int _errno;
-    mp_uint_t ret = self->nic_type->recv(self, (byte *)vstr.buf, len, &_errno);
+    mp_uint_t ret = self->nic_protocol->recv(self, (byte *)vstr.buf, len, &_errno);
     if (ret == -1) {
         mp_raise_OSError(_errno);
     }
@@ -318,7 +318,7 @@ STATIC mp_obj_t socket_sendto(mp_obj_t self_in, mp_obj_t data_in, mp_obj_t addr_
 
     // call the NIC to sendto
     int _errno;
-    mp_int_t ret = self->nic_type->sendto(self, bufinfo.buf, bufinfo.len, ip, port, &_errno);
+    mp_int_t ret = self->nic_protocol->sendto(self, bufinfo.buf, bufinfo.len, ip, port, &_errno);
     if (ret == -1) {
         mp_raise_OSError(_errno);
     }
@@ -339,7 +339,7 @@ STATIC mp_obj_t socket_recvfrom(mp_obj_t self_in, mp_obj_t len_in) {
     byte ip[4];
     mp_uint_t port;
     int _errno;
-    mp_int_t ret = self->nic_type->recvfrom(self, (byte *)vstr.buf, vstr.len, ip, &port, &_errno);
+    mp_int_t ret = self->nic_protocol->recvfrom(self, (byte *)vstr.buf, vstr.len, ip, &port, &_errno);
     if (ret == -1) {
         mp_raise_OSError(_errno);
     }
@@ -389,7 +389,7 @@ STATIC mp_obj_t socket_setsockopt(size_t n_args, const mp_obj_t *args) {
     }
 
     int _errno;
-    if (self->nic_type->setsockopt(self, level, opt, optval, optlen, &_errno) != 0) {
+    if (self->nic_protocol->setsockopt(self, level, opt, optval, optlen, &_errno) != 0) {
         mp_raise_OSError(_errno);
     }
 
@@ -429,7 +429,7 @@ STATIC mp_obj_t socket_settimeout(mp_obj_t self_in, mp_obj_t timeout_in) {
         #endif
     } else {
         int _errno;
-        if (self->nic_type->settimeout(self, timeout, &_errno) != 0) {
+        if (self->nic_protocol->settimeout(self, timeout, &_errno) != 0) {
             mp_raise_OSError(_errno);
         }
     }
@@ -477,7 +477,7 @@ mp_uint_t socket_read(mp_obj_t self_in, void *buf, mp_uint_t size, int *errcode)
     if (self->nic == MP_OBJ_NULL) {
         return MP_STREAM_ERROR;
     }
-    mp_int_t ret = self->nic_type->recv(self, (byte *)buf, size, errcode);
+    mp_int_t ret = self->nic_protocol->recv(self, (byte *)buf, size, errcode);
     if (ret < 0) {
         ret = MP_STREAM_ERROR;
     }
@@ -489,7 +489,7 @@ mp_uint_t socket_write(mp_obj_t self_in, const void *buf, mp_uint_t size, int *e
     if (self->nic == MP_OBJ_NULL) {
         return MP_STREAM_ERROR;
     }
-    mp_int_t ret = self->nic_type->send(self, buf, size, errcode);
+    mp_int_t ret = self->nic_protocol->send(self, buf, size, errcode);
     if (ret < 0) {
         ret = MP_STREAM_ERROR;
     }
@@ -500,7 +500,7 @@ mp_uint_t socket_ioctl(mp_obj_t self_in, mp_uint_t request, uintptr_t arg, int *
     mod_network_socket_obj_t *self = MP_OBJ_TO_PTR(self_in);
     if (request == MP_STREAM_CLOSE) {
         if (self->nic != MP_OBJ_NULL) {
-            self->nic_type->close(self);
+            self->nic_protocol->close(self);
             self->nic = MP_OBJ_NULL;
         }
         self->state = MOD_NETWORK_SS_CLOSED;
@@ -519,7 +519,7 @@ mp_uint_t socket_ioctl(mp_obj_t self_in, mp_uint_t request, uintptr_t arg, int *
         *errcode = MP_EINVAL;
         return MP_STREAM_ERROR;
     }
-    return self->nic_type->ioctl(self, request, arg, errcode);
+    return self->nic_protocol->ioctl(self, request, arg, errcode);
 }
 
 STATIC const mp_stream_p_t socket_stream_p = {
@@ -589,9 +589,9 @@ STATIC mp_obj_t mod_usocket_getaddrinfo(size_t n_args, const mp_obj_t *args) {
         // find a NIC that can do a name lookup
         for (mp_uint_t i = 0; i < MP_STATE_PORT(mod_network_nic_list).len; i++) {
             mp_obj_t nic = MP_STATE_PORT(mod_network_nic_list).items[i];
-            mod_network_nic_type_t *nic_type = (mod_network_nic_type_t *)mp_obj_get_type(nic);
-            if (nic_type->gethostbyname != NULL) {
-                int ret = nic_type->gethostbyname(nic, host, hlen, out_ip);
+            mod_network_nic_protocol_t *nic_protocol = (mod_network_nic_protocol_t *)MP_OBJ_TYPE_GET_SLOT(mp_obj_get_type(nic), protocol);
+            if (nic_protocol->gethostbyname != NULL) {
+                int ret = nic_protocol->gethostbyname(nic, host, hlen, out_ip);
                 if (ret != 0) {
                     mp_raise_OSError(ret);
                 }
diff --git a/extmod/network_ninaw10.c b/extmod/network_ninaw10.c
index 0852deabe9..8e806cb423 100644
--- a/extmod/network_ninaw10.c
+++ b/extmod/network_ninaw10.c
@@ -77,7 +77,7 @@ typedef struct _nina_obj_t {
 #define debug_printf(...) // mp_printf(&mp_plat_print, __VA_ARGS__)
 
 static uint16_t bind_port = BIND_PORT_RANGE_MIN;
-const mod_network_nic_type_t mod_network_nic_type_nina;
+const mp_obj_type_t mod_network_nic_type_nina;
 static nina_obj_t network_nina_wl_sta = {{(mp_obj_type_t *)&mod_network_nic_type_nina}, false, MOD_NETWORK_STA_IF};
 static nina_obj_t network_nina_wl_ap = {{(mp_obj_type_t *)&mod_network_nic_type_nina}, false, MOD_NETWORK_AP_IF};
 static mp_sched_node_t mp_wifi_sockpoll_node;
@@ -798,7 +798,7 @@ STATIC int network_ninaw10_socket_ioctl(mod_network_socket_obj_t *socket, mp_uin
     return ret;
 }
 
-static const mp_rom_map_elem_t nina_locals_dict_table[] = {
+STATIC const mp_rom_map_elem_t nina_locals_dict_table[] = {
     { MP_ROM_QSTR(MP_QSTR_active),              MP_ROM_PTR(&network_ninaw10_active_obj) },
     { MP_ROM_QSTR(MP_QSTR_scan),                MP_ROM_PTR(&network_ninaw10_scan_obj) },
     { MP_ROM_QSTR(MP_QSTR_connect),             MP_ROM_PTR(&network_ninaw10_connect_obj) },
@@ -817,18 +817,9 @@ static const mp_rom_map_elem_t nina_locals_dict_table[] = {
     { MP_ROM_QSTR(MP_QSTR_WPA_PSK),             MP_ROM_INT(NINA_SEC_WPA_PSK) },
 };
 
-static MP_DEFINE_CONST_DICT(nina_locals_dict, nina_locals_dict_table);
+STATIC MP_DEFINE_CONST_DICT(nina_locals_dict, nina_locals_dict_table);
 
-STATIC MP_DEFINE_CONST_OBJ_FULL_TYPE(
-    mod_network_nic_type_nina_base,
-    MP_QSTR_nina,
-    MP_TYPE_FLAG_NONE,
-    make_new, network_ninaw10_make_new,
-    locals_dict, &nina_locals_dict
-    );
-
-const mod_network_nic_type_t mod_network_nic_type_nina = {
-    .base = mod_network_nic_type_nina_base,
+STATIC const mod_network_nic_protocol_t mod_network_nic_protocol_nina = {
     .gethostbyname = network_ninaw10_gethostbyname,
     .socket = network_ninaw10_socket_socket,
     .close = network_ninaw10_socket_close,
@@ -845,6 +836,15 @@ const mod_network_nic_type_t mod_network_nic_type_nina = {
     .ioctl = network_ninaw10_socket_ioctl,
 };
 
+MP_DEFINE_CONST_OBJ_TYPE(
+    mod_network_nic_type_nina,
+    MP_QSTR_nina,
+    MP_TYPE_FLAG_NONE,
+    make_new, network_ninaw10_make_new,
+    locals_dict, &nina_locals_dict,
+    protocol, &mod_network_nic_protocol_nina
+    );
+
 MP_REGISTER_ROOT_POINTER(struct _machine_spi_obj_t *mp_wifi_spi);
 MP_REGISTER_ROOT_POINTER(struct _machine_timer_obj_t *mp_wifi_timer);
 MP_REGISTER_ROOT_POINTER(struct _mp_obj_list_t *mp_wifi_sockpoll_list);
diff --git a/extmod/network_wiznet5k.c b/extmod/network_wiznet5k.c
index 78cbff4ce2..eed656ee24 100644
--- a/extmod/network_wiznet5k.c
+++ b/extmod/network_wiznet5k.c
@@ -1017,24 +1017,9 @@ STATIC const mp_rom_map_elem_t wiznet5k_locals_dict_table[] = {
 STATIC MP_DEFINE_CONST_DICT(wiznet5k_locals_dict, wiznet5k_locals_dict_table);
 
 #if WIZNET5K_WITH_LWIP_STACK
-MP_DEFINE_CONST_OBJ_TYPE(
-    mod_network_nic_type_wiznet5k,
-    MP_QSTR_WIZNET5K,
-    MP_TYPE_FLAG_NONE,
-    make_new, wiznet5k_make_new,
-    locals_dict, &wiznet5k_locals_dict
-    );
+#define NIC_TYPE_WIZNET_PROTOCOL
 #else // WIZNET5K_PROVIDED_STACK
-STATIC MP_DEFINE_CONST_OBJ_FULL_TYPE(
-    mod_network_nic_type_wiznet5k_base,
-    MP_QSTR_WIZNET5K,
-    MP_TYPE_FLAG_NONE,
-    make_new, wiznet5k_make_new,
-    locals_dict, &wiznet5k_locals_dict
-    );
-
-const mod_network_nic_type_t mod_network_nic_type_wiznet5k = {
-    .base = mod_network_nic_type_wiznet5k_base,
+const mod_network_nic_protocol_t mod_network_nic_protocol_wiznet = {
     .gethostbyname = wiznet5k_gethostbyname,
     .socket = wiznet5k_socket_socket,
     .close = wiznet5k_socket_close,
@@ -1050,6 +1035,16 @@ const mod_network_nic_type_t mod_network_nic_type_wiznet5k = {
     .settimeout = wiznet5k_socket_settimeout,
     .ioctl = wiznet5k_socket_ioctl,
 };
+#define NIC_TYPE_WIZNET_PROTOCOL protocol, &mod_network_nic_protocol_wiznet,
 #endif
 
+MP_DEFINE_CONST_OBJ_TYPE(
+    mod_network_nic_type_wiznet5k,
+    MP_QSTR_WIZNET5K,
+    MP_TYPE_FLAG_NONE,
+    make_new, wiznet5k_make_new,
+    NIC_TYPE_WIZNET_PROTOCOL
+    locals_dict, &wiznet5k_locals_dict
+    );
+
 #endif // MICROPY_PY_NETWORK_WIZNET5K
diff --git a/ports/rp2/mpconfigport.h b/ports/rp2/mpconfigport.h
index d5e4de7b5a..a21c141e4b 100644
--- a/ports/rp2/mpconfigport.h
+++ b/ports/rp2/mpconfigport.h
@@ -176,18 +176,14 @@ extern const struct _mp_obj_type_t mp_network_cyw43_type;
 #ifndef MICROPY_PY_USOCKET_EXTENDED_STATE
 #define MICROPY_PY_USOCKET_EXTENDED_STATE   (1)
 #endif
-extern const struct _mod_network_nic_type_t mod_network_nic_type_nina;
+extern const struct _mp_obj_type_t mod_network_nic_type_nina;
 #define MICROPY_HW_NIC_NINAW10              { MP_ROM_QSTR(MP_QSTR_WLAN), MP_ROM_PTR(&mod_network_nic_type_nina) },
 #else
 #define MICROPY_HW_NIC_NINAW10
 #endif
 
 #if MICROPY_PY_NETWORK_WIZNET5K
-#if MICROPY_PY_LWIP
 extern const struct _mp_obj_type_t mod_network_nic_type_wiznet5k;
-#else
-extern const struct _mod_network_nic_type_t mod_network_nic_type_wiznet5k;
-#endif
 #define MICROPY_HW_NIC_WIZNET5K             { MP_ROM_QSTR(MP_QSTR_WIZNET5K), MP_ROM_PTR(&mod_network_nic_type_wiznet5k) },
 #else
 #define MICROPY_HW_NIC_WIZNET5K
diff --git a/ports/stm32/mpconfigport.h b/ports/stm32/mpconfigport.h
index de12f03207..2898b01a38 100644
--- a/ports/stm32/mpconfigport.h
+++ b/ports/stm32/mpconfigport.h
@@ -191,11 +191,7 @@ extern const struct _mp_obj_type_t mp_network_cyw43_type;
 #endif
 
 #if MICROPY_PY_NETWORK_WIZNET5K
-#if MICROPY_PY_LWIP
 extern const struct _mp_obj_type_t mod_network_nic_type_wiznet5k;
-#else
-extern const struct _mod_network_nic_type_t mod_network_nic_type_wiznet5k;
-#endif
 #define MICROPY_HW_NIC_WIZNET5K             { MP_ROM_QSTR(MP_QSTR_WIZNET5K), MP_ROM_PTR(&mod_network_nic_type_wiznet5k) },
 #else
 #define MICROPY_HW_NIC_WIZNET5K