diff --git a/extmod/moductypes.c b/extmod/moductypes.c
index e627cd1462..9eea30bf3e 100644
--- a/extmod/moductypes.c
+++ b/extmod/moductypes.c
@@ -122,8 +122,8 @@ STATIC NORETURN void syntax_error(void) {
     mp_raise_TypeError(translate("syntax error in uctypes descriptor"));
 }
 
-STATIC mp_obj_t uctypes_struct_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args) {
-    mp_arg_check_num(n_args, n_kw, 2, 3, false);
+STATIC mp_obj_t uctypes_struct_make_new(const mp_obj_type_t *type, size_t n_args, const mp_obj_t *args, mp_map_t *kw_args) {
+    mp_arg_check_num(n_args, kw_args, 2, 3, false);
     mp_obj_uctypes_struct_t *o = m_new_obj(mp_obj_uctypes_struct_t);
     o->base.type = type;
     o->addr = (void*)(uintptr_t)mp_obj_int_get_truncated(args[0]);
diff --git a/extmod/modutimeq.c b/extmod/modutimeq.c
index 614820443b..99b51016d8 100644
--- a/extmod/modutimeq.c
+++ b/extmod/modutimeq.c
@@ -76,8 +76,8 @@ STATIC bool time_less_than(struct qentry *item, struct qentry *parent) {
     return res && res < (MODULO / 2);
 }
 
-STATIC mp_obj_t utimeq_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args) {
-    mp_arg_check_num(n_args, n_kw, 1, 1, false);
+STATIC mp_obj_t utimeq_make_new(const mp_obj_type_t *type, size_t n_args, const mp_obj_t *args, mp_map_t *kw_args) {
+    mp_arg_check_num(n_args, kw_args, 1, 1, false);
     mp_uint_t alloc = mp_obj_get_int(args[0]);
     mp_obj_utimeq_t *o = m_new_obj_var(mp_obj_utimeq_t, struct qentry, alloc);
     o->base.type = type;
diff --git a/extmod/moduzlib.c b/extmod/moduzlib.c
index 253deac1e6..7f15d02a8e 100644
--- a/extmod/moduzlib.c
+++ b/extmod/moduzlib.c
@@ -69,8 +69,8 @@ STATIC int read_src_stream(TINF_DATA *data) {
     return c;
 }
 
-STATIC mp_obj_t decompio_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args) {
-    mp_arg_check_num(n_args, n_kw, 1, 2, false);
+STATIC mp_obj_t decompio_make_new(const mp_obj_type_t *type, size_t n_args, const mp_obj_t *args, mp_map_t *kw_args) {
+    mp_arg_check_num(n_args, kw_args, 1, 2, false);
     mp_get_stream_raise(args[0], MP_STREAM_OP_READ);
     mp_obj_decompio_t *o = m_new_obj(mp_obj_decompio_t);
     o->base.type = type;
diff --git a/extmod/modwebsocket.c b/extmod/modwebsocket.c
index c556f2b770..997c7e2625 100644
--- a/extmod/modwebsocket.c
+++ b/extmod/modwebsocket.c
@@ -57,8 +57,8 @@ typedef struct _mp_obj_websocket_t {
 
 STATIC mp_uint_t websocket_write(mp_obj_t self_in, const void *buf, mp_uint_t size, int *errcode);
 
-STATIC mp_obj_t websocket_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args) {
-    mp_arg_check_num(n_args, n_kw, 1, 2, false);
+STATIC mp_obj_t websocket_make_new(const mp_obj_type_t *type, size_t n_args, const mp_obj_t *args, mp_map_t *kw_args) {
+    mp_arg_check_num(n_args, kw_args, 1, 2, false);
     mp_get_stream_raise(args[0], MP_STREAM_OP_READ | MP_STREAM_OP_WRITE | MP_STREAM_OP_IOCTL);
     mp_obj_websocket_t *o = m_new_obj(mp_obj_websocket_t);
     o->base.type = type;
diff --git a/ports/unix/file.c b/ports/unix/file.c
index 98ac1b3cc2..c0cf6dcc43 100644
--- a/ports/unix/file.c
+++ b/ports/unix/file.c
@@ -205,9 +205,9 @@ STATIC mp_obj_t fdfile_open(const mp_obj_type_t *type, mp_arg_val_t *args) {
     return MP_OBJ_FROM_PTR(o);
 }
 
-STATIC mp_obj_t fdfile_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args) {
+STATIC mp_obj_t fdfile_make_new(const mp_obj_type_t *type, size_t n_args, const mp_obj_t *args, mp_map_t *kw_args) {
     mp_arg_val_t arg_vals[FILE_OPEN_NUM_ARGS];
-    mp_arg_parse_all_kw_array(n_args, n_kw, args, FILE_OPEN_NUM_ARGS, file_open_args, arg_vals);
+    mp_arg_parse_all(n_args, args, kw_args, FILE_OPEN_NUM_ARGS, file_open_args, arg_vals);
     return fdfile_open(type, arg_vals);
 }
 
diff --git a/ports/unix/modffi.c b/ports/unix/modffi.c
index fcbcebc390..03dc9e4ec6 100644
--- a/ports/unix/modffi.c
+++ b/ports/unix/modffi.c
@@ -304,9 +304,9 @@ STATIC mp_obj_t ffimod_addr(mp_obj_t self_in, mp_obj_t symname_in) {
 }
 MP_DEFINE_CONST_FUN_OBJ_2(ffimod_addr_obj, ffimod_addr);
 
-STATIC mp_obj_t ffimod_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args) {
+STATIC mp_obj_t ffimod_make_new(const mp_obj_type_t *type, size_t n_args, const mp_obj_t *args, mp_map_t *kw_args) {
     (void)n_args;
-    (void)n_kw;
+    (void)kw_args;
 
     const char *fname = NULL;
     if (args[0] != mp_const_none) {
@@ -481,7 +481,7 @@ STATIC const mp_obj_type_t opaque_type = {
 */
 
 STATIC mp_obj_t mod_ffi_open(size_t n_args, const mp_obj_t *args) {
-    return ffimod_make_new(&ffimod_type, n_args, 0, args);
+    return ffimod_make_new(&ffimod_type, n_args, args, NULL);
 }
 MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mod_ffi_open_obj, 1, 2, mod_ffi_open);
 
diff --git a/ports/unix/modusocket.c b/ports/unix/modusocket.c
index 9b9869f5b1..84e9298fd3 100644
--- a/ports/unix/modusocket.c
+++ b/ports/unix/modusocket.c
@@ -325,9 +325,9 @@ STATIC mp_obj_t socket_makefile(size_t n_args, const mp_obj_t *args) {
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(socket_makefile_obj, 1, 3, socket_makefile);
 
-STATIC mp_obj_t socket_make_new(const mp_obj_type_t *type_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
+STATIC mp_obj_t socket_make_new(const mp_obj_type_t *type_in, size_t n_args, const mp_obj_t *args, mp_map_t *kw_args) {
     (void)type_in;
-    (void)n_kw;
+    (void)kw_args;
 
     int family = AF_INET;
     int type = SOCK_STREAM;
diff --git a/py/modio.c b/py/modio.c
index 9b09de96e4..9918159cb5 100644
--- a/py/modio.c
+++ b/py/modio.c
@@ -46,11 +46,11 @@ STATIC const mp_obj_type_t mp_type_iobase;
 
 STATIC mp_obj_base_t iobase_singleton = {&mp_type_iobase};
 
-STATIC mp_obj_t iobase_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args) {
+STATIC mp_obj_t iobase_make_new(const mp_obj_type_t *type, size_t n_args, const mp_obj_t *args, mp_map_t *kw_args) {
     (void)type;
     (void)n_args;
-    (void)n_kw;
     (void)args;
+    (void)kw_args;
     return MP_OBJ_FROM_PTR(&iobase_singleton);
 }
 
diff --git a/py/objdeque.c b/py/objdeque.c
index dd0141831d..b2785b5b60 100644
--- a/py/objdeque.c
+++ b/py/objdeque.c
@@ -44,8 +44,8 @@ typedef struct _mp_obj_deque_t {
     #define FLAG_CHECK_OVERFLOW 1
 } mp_obj_deque_t;
 
-STATIC mp_obj_t deque_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args) {
-    mp_arg_check_num(n_args, n_kw, 2, 3, false);
+STATIC mp_obj_t deque_make_new(const mp_obj_type_t *type, size_t n_args, const mp_obj_t *args, mp_map_t *kw_args) {
+    mp_arg_check_num(n_args, kw_args, 2, 3, false);
 
     /* Initialization from existing sequence is not supported, so an empty
        tuple must be passed as such. */
diff --git a/py/objfun.c b/py/objfun.c
index 2ada0b3f16..b8364815be 100644
--- a/py/objfun.c
+++ b/py/objfun.c
@@ -436,7 +436,7 @@ typedef mp_uint_t (*viper_fun_4_t)(mp_uint_t, mp_uint_t, mp_uint_t, mp_uint_t);
 STATIC mp_obj_t fun_viper_call(mp_obj_t self_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
     mp_obj_fun_viper_t *self = self_in;
 
-    mp_arg_check_num(n_args, n_kw, self->n_args, self->n_args, false);
+    mp_arg_check_num_kw_array(n_args, n_kw, self->n_args, self->n_args, false);
 
     void *fun = MICROPY_MAKE_POINTER_CALLABLE(self->fun_data);