diff --git a/shared-bindings/wiznet/wiznet5k.c b/shared-bindings/wiznet/wiznet5k.c
index 6d43e8992d..b8b7ea8a0d 100644
--- a/shared-bindings/wiznet/wiznet5k.c
+++ b/shared-bindings/wiznet/wiznet5k.c
@@ -41,6 +41,7 @@
 #include "shared-bindings/digitalio/DigitalInOut.h"
 #include "shared-bindings/digitalio/DriveMode.h"
 #include "shared-bindings/busio/SPI.h"
+#include "shared-bindings/microcontroller/Pin.h"
 
 #include "shared-module/network/__init__.h"
 #include "shared-module/wiznet/wiznet5k.h"
@@ -56,14 +57,27 @@
 //|
 //|   :param spi: spi bus to use
 //|   :param cs: pin to use for Chip Select
-//|   :param rst: pin to sue for Reset
+//|   :param rst: pin to use for Reset
 //|
 
-STATIC mp_obj_t wiznet5k_make_new(const mp_obj_type_t *type, size_t n_args, const mp_obj_t *args, mp_map_t *kw_args) {
-    // check arguments
-    mp_arg_check_num(n_args, kw_args, 3, 3, false);
+STATIC mp_obj_t wiznet5k_make_new(const mp_obj_type_t *type, size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
+    enum { ARG_spi, ARG_cs, ARG_rst, ARG_dhcp };
+    static const mp_arg_t allowed_args[] = {
+        { MP_QSTR_spi, MP_ARG_REQUIRED | MP_ARG_OBJ },
+        { MP_QSTR_cs, MP_ARG_REQUIRED | MP_ARG_OBJ },
+        { MP_QSTR_rst, MP_ARG_REQUIRED | MP_ARG_OBJ },
+        { MP_QSTR_dhcp, MP_ARG_KW_ONLY | MP_ARG_BOOL, { .u_bool = true } },
+    };
+    mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
+    mp_arg_parse_all(n_args, pos_args, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
+    // XXX check type of ARG_spi?
+    // XXX should ARG_rst be optional?
+    assert_pin(args[ARG_cs].u_obj, false);
+    assert_pin(args[ARG_rst].u_obj, false);
 
-    return wiznet5k_create(args[0], args[1], args[2]);
+    mp_obj_t ret = wiznet5k_create(args[ARG_spi].u_obj, args[ARG_cs].u_obj, args[ARG_rst].u_obj);
+    if (args[ARG_dhcp].u_bool) wiznet5k_start_dhcp();
+    return ret;
 }
 
 //| .. attribute:: connected
@@ -99,9 +113,11 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_1(wiznet5k_dhcp_get_value_obj, wiznet5k_dhcp_get_
 STATIC mp_obj_t wiznet5k_dhcp_set_value(mp_obj_t self_in, mp_obj_t value) {
     (void)self_in;
     if (mp_obj_is_true(value)) {
-        wiznet5k_start_dhcp();
+        int ret = wiznet5k_start_dhcp();
+        if (ret) mp_raise_OSError(ret);
     } else {
-        wiznet5k_stop_dhcp();
+        int ret = wiznet5k_stop_dhcp();
+        if (ret) mp_raise_OSError(ret);
     }
     return mp_const_none;
 }
diff --git a/shared-module/wiznet/wiznet5k.c b/shared-module/wiznet/wiznet5k.c
index 660df90b75..237f678879 100644
--- a/shared-module/wiznet/wiznet5k.c
+++ b/shared-module/wiznet/wiznet5k.c
@@ -328,27 +328,29 @@ void wiznet5k_socket_timer_tick(mod_network_socket_obj_t *socket) {
     }
 }
 
-void wiznet5k_start_dhcp(void) {
+int wiznet5k_start_dhcp(void) {
     // XXX this should throw an error if DHCP fails
     static DHCP_INIT_BUFFER_TYPE dhcp_buf[DHCP_INIT_BUFFER_SIZE];
 
     if (wiznet5k_obj.dhcp_socket < 0) {
         // Set up the socket to listen on UDP 68 before calling DHCP_init
         wiznet5k_obj.dhcp_socket = get_available_socket(&wiznet5k_obj);
-        if (wiznet5k_obj.dhcp_socket < 0) return;
+        if (wiznet5k_obj.dhcp_socket < 0) return MP_EMFILE;
 
         WIZCHIP_EXPORT(socket)(wiznet5k_obj.dhcp_socket, MOD_NETWORK_SOCK_DGRAM, DHCP_CLIENT_PORT, 0);
         DHCP_init(wiznet5k_obj.dhcp_socket, dhcp_buf);
     }
+    return 0;
 }
 
-void wiznet5k_stop_dhcp(void) {
+int wiznet5k_stop_dhcp(void) {
     if (wiznet5k_obj.dhcp_socket >= 0) {
         DHCP_stop();
         WIZCHIP_EXPORT(close)(wiznet5k_obj.dhcp_socket);
         wiznet5k_obj.socket_used &= ~(1 << wiznet5k_obj.dhcp_socket);
         wiznet5k_obj.dhcp_socket = -1;
     }
+    return 0;
 }
 
 bool wiznet5k_check_dhcp(void) {
@@ -403,9 +405,6 @@ mp_obj_t wiznet5k_create(mp_obj_t spi_in, mp_obj_t cs_in, mp_obj_t rst_in) {
     // seems we need a small delay after init
     mp_hal_delay_ms(250);
 
-    // dhcp is started by default
-    wiznet5k_start_dhcp();
-
     // register with network module
     network_module_register_nic(&wiznet5k_obj);
 
diff --git a/shared-module/wiznet/wiznet5k.h b/shared-module/wiznet/wiznet5k.h
index 09f83df66f..2cfb17a209 100644
--- a/shared-module/wiznet/wiznet5k.h
+++ b/shared-module/wiznet/wiznet5k.h
@@ -39,7 +39,7 @@ typedef struct _wiznet5k_obj_t {
     digitalio_digitalinout_obj_t cs;
     digitalio_digitalinout_obj_t rst;
     uint8_t socket_used;
-    int8_t dhcp_socket;
+    int8_t dhcp_socket; // -1 for DHCP not in use
 } wiznet5k_obj_t;
 
 int wiznet5k_gethostbyname(mp_obj_t nic, const char *name, mp_uint_t len, uint8_t *out_ip);
@@ -60,8 +60,8 @@ void wiznet5k_socket_timer_tick(mod_network_socket_obj_t *socket);
 mp_obj_t wiznet5k_socket_disconnect(mp_obj_t self_in);
 mp_obj_t wiznet5k_create(mp_obj_t spi_in, mp_obj_t cs_in, mp_obj_t rst_in);
 
-void wiznet5k_start_dhcp(void);
-void wiznet5k_stop_dhcp(void);
+int wiznet5k_start_dhcp(void);
+int wiznet5k_stop_dhcp(void);
 bool wiznet5k_check_dhcp(void);
 
 extern const mod_network_nic_type_t mod_network_nic_type_wiznet5k;