diff --git a/extmod/moductypes.c b/extmod/moductypes.c
index 48cbfad52d..cd7e9d1782 100644
--- a/extmod/moductypes.c
+++ b/extmod/moductypes.c
@@ -121,7 +121,7 @@ STATIC NORETURN void syntax_error(void) {
     nlr_raise(mp_obj_new_exception_msg(&mp_type_TypeError, "syntax error in uctypes descriptor"));
 }
 
-STATIC mp_obj_t uctypes_struct_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
+STATIC mp_obj_t uctypes_struct_make_new(mp_obj_t type_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
     mp_arg_check_num(n_args, n_kw, 2, 3, false);
     mp_obj_uctypes_struct_t *o = m_new_obj(mp_obj_uctypes_struct_t);
     o->base.type = MP_OBJ_TO_PTR(type_in);
diff --git a/extmod/moduhashlib.c b/extmod/moduhashlib.c
index a824bd0eb3..6ddfa6141b 100644
--- a/extmod/moduhashlib.c
+++ b/extmod/moduhashlib.c
@@ -41,7 +41,7 @@ typedef struct _mp_obj_hash_t {
 
 STATIC mp_obj_t hash_update(mp_obj_t self_in, mp_obj_t arg);
 
-STATIC mp_obj_t hash_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
+STATIC mp_obj_t hash_make_new(mp_obj_t type_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
     mp_arg_check_num(n_args, n_kw, 0, 1, false);
     mp_obj_hash_t *o = m_new_obj_var(mp_obj_hash_t, char, sizeof(CRYAL_SHA256_CTX));
     o->base.type = MP_OBJ_TO_PTR(type_in);
diff --git a/py/obj.h b/py/obj.h
index 58221bf06d..88767bf1ae 100644
--- a/py/obj.h
+++ b/py/obj.h
@@ -408,8 +408,8 @@ typedef enum {
 } mp_print_kind_t;
 
 typedef void (*mp_print_fun_t)(const mp_print_t *print, mp_obj_t o, mp_print_kind_t kind);
-typedef mp_obj_t (*mp_make_new_fun_t)(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args);
-typedef mp_obj_t (*mp_call_fun_t)(mp_obj_t fun, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args);
+typedef mp_obj_t (*mp_make_new_fun_t)(mp_obj_t type_in, size_t n_args, size_t n_kw, const mp_obj_t *args);
+typedef mp_obj_t (*mp_call_fun_t)(mp_obj_t fun, size_t n_args, size_t n_kw, const mp_obj_t *args);
 typedef mp_obj_t (*mp_unary_op_fun_t)(mp_uint_t op, mp_obj_t);
 typedef mp_obj_t (*mp_binary_op_fun_t)(mp_uint_t op, mp_obj_t, mp_obj_t);
 typedef void (*mp_attr_fun_t)(mp_obj_t self_in, qstr attr, mp_obj_t *dest);
@@ -691,7 +691,7 @@ void mp_obj_exception_clear_traceback(mp_obj_t self_in);
 void mp_obj_exception_add_traceback(mp_obj_t self_in, qstr file, size_t line, qstr block);
 void mp_obj_exception_get_traceback(mp_obj_t self_in, size_t *n, size_t **values);
 mp_obj_t mp_obj_exception_get_value(mp_obj_t self_in);
-mp_obj_t mp_obj_exception_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args);
+mp_obj_t mp_obj_exception_make_new(mp_obj_t type_in, size_t n_args, size_t n_kw, const mp_obj_t *args);
 mp_obj_t mp_alloc_emergency_exception_buf(mp_obj_t size_in);
 void mp_init_emergency_exception_buf(void);
 
diff --git a/py/objarray.c b/py/objarray.c
index 3445bff82e..2c4813f54f 100644
--- a/py/objarray.c
+++ b/py/objarray.c
@@ -168,7 +168,7 @@ STATIC mp_obj_t array_construct(char typecode, mp_obj_t initializer) {
 #endif
 
 #if MICROPY_PY_ARRAY
-STATIC mp_obj_t array_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
+STATIC mp_obj_t array_make_new(mp_obj_t type_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
     (void)type_in;
     mp_arg_check_num(n_args, n_kw, 1, 2, false);
 
@@ -187,7 +187,7 @@ STATIC mp_obj_t array_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_k
 #endif
 
 #if MICROPY_PY_BUILTINS_BYTEARRAY
-STATIC mp_obj_t bytearray_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
+STATIC mp_obj_t bytearray_make_new(mp_obj_t type_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
     (void)type_in;
     mp_arg_check_num(n_args, n_kw, 0, 1, false);
 
@@ -219,7 +219,7 @@ mp_obj_t mp_obj_new_memoryview(byte typecode, mp_uint_t nitems, void *items) {
     return MP_OBJ_FROM_PTR(self);
 }
 
-STATIC mp_obj_t memoryview_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
+STATIC mp_obj_t memoryview_make_new(mp_obj_t type_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
     (void)type_in;
 
     // TODO possibly allow memoryview constructor to take start/stop so that one
diff --git a/py/objbool.c b/py/objbool.c
index 4276335635..09878a7505 100644
--- a/py/objbool.c
+++ b/py/objbool.c
@@ -52,7 +52,7 @@ STATIC void bool_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_
     }
 }
 
-STATIC mp_obj_t bool_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
+STATIC mp_obj_t bool_make_new(mp_obj_t type_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
     (void)type_in;
     mp_arg_check_num(n_args, n_kw, 0, 1, false);
 
diff --git a/py/objboundmeth.c b/py/objboundmeth.c
index c191923979..c0e75eae97 100644
--- a/py/objboundmeth.c
+++ b/py/objboundmeth.c
@@ -47,7 +47,7 @@ STATIC void bound_meth_print(const mp_print_t *print, mp_obj_t o_in, mp_print_ki
 }
 #endif
 
-STATIC mp_obj_t bound_meth_call(mp_obj_t self_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
+STATIC mp_obj_t bound_meth_call(mp_obj_t self_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
     mp_obj_bound_meth_t *self = MP_OBJ_TO_PTR(self_in);
 
     // need to insert self->self before all other args and then call self->meth
diff --git a/py/objclosure.c b/py/objclosure.c
index e331a659bb..d556b3b8ae 100644
--- a/py/objclosure.c
+++ b/py/objclosure.c
@@ -36,7 +36,7 @@ typedef struct _mp_obj_closure_t {
     mp_obj_t closed[];
 } mp_obj_closure_t;
 
-STATIC mp_obj_t closure_call(mp_obj_t self_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
+STATIC mp_obj_t closure_call(mp_obj_t self_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
     mp_obj_closure_t *self = MP_OBJ_TO_PTR(self_in);
 
     // need to concatenate closed-over-vars and args
diff --git a/py/objcomplex.c b/py/objcomplex.c
index e9a15d2547..df0467e324 100644
--- a/py/objcomplex.c
+++ b/py/objcomplex.c
@@ -69,7 +69,7 @@ STATIC void complex_print(const mp_print_t *print, mp_obj_t o_in, mp_print_kind_
     }
 }
 
-STATIC mp_obj_t complex_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
+STATIC mp_obj_t complex_make_new(mp_obj_t type_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
     (void)type_in;
     mp_arg_check_num(n_args, n_kw, 0, 2, false);
 
diff --git a/py/objdict.c b/py/objdict.c
index f3217507a9..4010d9ce3f 100644
--- a/py/objdict.c
+++ b/py/objdict.c
@@ -82,7 +82,7 @@ STATIC void dict_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_
     }
 }
 
-STATIC mp_obj_t dict_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
+STATIC mp_obj_t dict_make_new(mp_obj_t type_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
     mp_obj_t dict_out = mp_obj_new_dict(0);
     mp_obj_dict_t *dict = MP_OBJ_TO_PTR(dict_out);
     dict->base.type = MP_OBJ_TO_PTR(type_in);
diff --git a/py/objenumerate.c b/py/objenumerate.c
index 3629c1a20b..46c3e801df 100644
--- a/py/objenumerate.c
+++ b/py/objenumerate.c
@@ -45,7 +45,7 @@ STATIC const mp_arg_t enumerate_make_new_args[] = {
 };
 #define ENUMERATE_MAKE_NEW_NUM_ARGS MP_ARRAY_SIZE(enumerate_make_new_args)
 
-STATIC mp_obj_t enumerate_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
+STATIC mp_obj_t enumerate_make_new(mp_obj_t type_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
 #if MICROPY_CPYTHON_COMPAT
     // parse args
     mp_arg_val_t vals[ENUMERATE_MAKE_NEW_NUM_ARGS];
diff --git a/py/objexcept.c b/py/objexcept.c
index ffe5ea0416..6e28a980bd 100644
--- a/py/objexcept.c
+++ b/py/objexcept.c
@@ -114,7 +114,7 @@ STATIC void mp_obj_exception_print(const mp_print_t *print, mp_obj_t o_in, mp_pr
     mp_obj_tuple_print(print, MP_OBJ_FROM_PTR(o->args), kind);
 }
 
-mp_obj_t mp_obj_exception_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
+mp_obj_t mp_obj_exception_make_new(mp_obj_t type_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
     mp_arg_check_num(n_args, n_kw, 0, MP_OBJ_FUN_ARGS_MAX, false);
     mp_obj_exception_t *o = m_new_obj_var_maybe(mp_obj_exception_t, mp_obj_t, 0);
     if (o == NULL) {
diff --git a/py/objfilter.c b/py/objfilter.c
index cc3083c96c..168f0e7612 100644
--- a/py/objfilter.c
+++ b/py/objfilter.c
@@ -34,7 +34,7 @@ typedef struct _mp_obj_filter_t {
     mp_obj_t iter;
 } mp_obj_filter_t;
 
-STATIC mp_obj_t filter_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
+STATIC mp_obj_t filter_make_new(mp_obj_t type_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
     mp_arg_check_num(n_args, n_kw, 2, 2, false);
     mp_obj_filter_t *o = m_new_obj(mp_obj_filter_t);
     o->base.type = MP_OBJ_TO_PTR(type_in);
diff --git a/py/objfloat.c b/py/objfloat.c
index 051c0f61c3..f144bfd864 100644
--- a/py/objfloat.c
+++ b/py/objfloat.c
@@ -69,7 +69,7 @@ STATIC void float_print(const mp_print_t *print, mp_obj_t o_in, mp_print_kind_t
     }
 }
 
-STATIC mp_obj_t float_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
+STATIC mp_obj_t float_make_new(mp_obj_t type_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
     (void)type_in;
     mp_arg_check_num(n_args, n_kw, 0, 1, false);
 
diff --git a/py/objfun.c b/py/objfun.c
index a574926ba5..f2cc34fad6 100644
--- a/py/objfun.c
+++ b/py/objfun.c
@@ -52,7 +52,7 @@
 
 // mp_obj_fun_builtin_t defined in obj.h
 
-STATIC mp_obj_t fun_builtin_call(mp_obj_t self_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
+STATIC mp_obj_t fun_builtin_call(mp_obj_t self_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
     assert(MP_OBJ_IS_TYPE(self_in, &mp_type_fun_builtin));
     mp_obj_fun_builtin_t *self = MP_OBJ_TO_PTR(self_in);
 
@@ -196,7 +196,7 @@ mp_code_state *mp_obj_fun_bc_prepare_codestate(mp_obj_t self_in, size_t n_args,
 }
 #endif
 
-STATIC mp_obj_t fun_bc_call(mp_obj_t self_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
+STATIC mp_obj_t fun_bc_call(mp_obj_t self_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
     MP_STACK_CHECK();
 
     DEBUG_printf("Input n_args: " UINT_FMT ", n_kw: " UINT_FMT "\n", n_args, n_kw);
@@ -353,7 +353,7 @@ mp_obj_t mp_obj_new_fun_bc(mp_obj_t def_args_in, mp_obj_t def_kw_args, const byt
 
 #if MICROPY_EMIT_NATIVE
 
-STATIC mp_obj_t fun_native_call(mp_obj_t self_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
+STATIC mp_obj_t fun_native_call(mp_obj_t self_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
     MP_STACK_CHECK();
     mp_obj_fun_bc_t *self = self_in;
     mp_call_fun_t fun = MICROPY_MAKE_POINTER_CALLABLE((void*)self->bytecode);
@@ -393,7 +393,7 @@ typedef mp_uint_t (*viper_fun_2_t)(mp_uint_t, mp_uint_t);
 typedef mp_uint_t (*viper_fun_3_t)(mp_uint_t, mp_uint_t, mp_uint_t);
 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, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
+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);
@@ -514,7 +514,7 @@ STATIC mp_obj_t convert_val_from_inline_asm(mp_uint_t val) {
     return MP_OBJ_NEW_SMALL_INT(val);
 }
 
-STATIC mp_obj_t fun_asm_call(mp_obj_t self_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
+STATIC mp_obj_t fun_asm_call(mp_obj_t self_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
     mp_obj_fun_asm_t *self = self_in;
 
     mp_arg_check_num(n_args, n_kw, self->n_args, self->n_args, false);
diff --git a/py/objgenerator.c b/py/objgenerator.c
index 0a68485628..91936f92f3 100644
--- a/py/objgenerator.c
+++ b/py/objgenerator.c
@@ -49,7 +49,7 @@ typedef struct _mp_obj_gen_instance_t {
     mp_code_state code_state;
 } mp_obj_gen_instance_t;
 
-STATIC mp_obj_t gen_wrap_call(mp_obj_t self_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
+STATIC mp_obj_t gen_wrap_call(mp_obj_t self_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
     mp_obj_gen_wrap_t *self = MP_OBJ_TO_PTR(self_in);
     mp_obj_fun_bc_t *self_fun = (mp_obj_fun_bc_t*)self->fun;
     assert(self_fun->base.type == &mp_type_fun_bc);
diff --git a/py/objint.c b/py/objint.c
index 57fe364dcf..7ee7653cad 100644
--- a/py/objint.c
+++ b/py/objint.c
@@ -42,7 +42,7 @@
 #endif
 
 // This dispatcher function is expected to be independent of the implementation of long int
-STATIC mp_obj_t mp_obj_int_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
+STATIC mp_obj_t mp_obj_int_make_new(mp_obj_t type_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
     (void)type_in;
     mp_arg_check_num(n_args, n_kw, 0, 2, false);
 
diff --git a/py/objlist.c b/py/objlist.c
index d0641f21c2..059fec1b25 100644
--- a/py/objlist.c
+++ b/py/objlist.c
@@ -68,7 +68,7 @@ STATIC mp_obj_t list_extend_from_iter(mp_obj_t list, mp_obj_t iterable) {
     return list;
 }
 
-STATIC mp_obj_t list_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
+STATIC mp_obj_t list_make_new(mp_obj_t type_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
     (void)type_in;
     mp_arg_check_num(n_args, n_kw, 0, 1, false);
 
diff --git a/py/objmap.c b/py/objmap.c
index 6dbfaca05f..a0293c36f8 100644
--- a/py/objmap.c
+++ b/py/objmap.c
@@ -36,7 +36,7 @@ typedef struct _mp_obj_map_t {
     mp_obj_t iters[];
 } mp_obj_map_t;
 
-STATIC mp_obj_t map_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
+STATIC mp_obj_t map_make_new(mp_obj_t type_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
     mp_arg_check_num(n_args, n_kw, 2, MP_OBJ_FUN_ARGS_MAX, false);
     mp_obj_map_t *o = m_new_obj_var(mp_obj_map_t, mp_obj_t, n_args - 1);
     o->base.type = MP_OBJ_TO_PTR(type_in);
diff --git a/py/objnamedtuple.c b/py/objnamedtuple.c
index 167e23b4a4..3e34603263 100644
--- a/py/objnamedtuple.c
+++ b/py/objnamedtuple.c
@@ -77,7 +77,7 @@ STATIC void namedtuple_attr(mp_obj_t self_in, qstr attr, mp_obj_t *dest) {
     }
 }
 
-STATIC mp_obj_t namedtuple_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
+STATIC mp_obj_t namedtuple_make_new(mp_obj_t type_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
     mp_obj_namedtuple_type_t *type = MP_OBJ_TO_PTR(type_in);
     mp_uint_t num_fields = type->n_fields;
     if (n_args + n_kw != num_fields) {
diff --git a/py/objobject.c b/py/objobject.c
index afb9d5af72..5cd3773940 100644
--- a/py/objobject.c
+++ b/py/objobject.c
@@ -33,7 +33,7 @@ typedef struct _mp_obj_object_t {
     mp_obj_base_t base;
 } mp_obj_object_t;
 
-STATIC mp_obj_t object_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
+STATIC mp_obj_t object_make_new(mp_obj_t type_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
     (void)args;
     mp_arg_check_num(n_args, n_kw, 0, 0, false);
     mp_obj_object_t *o = m_new_obj(mp_obj_object_t);
diff --git a/py/objproperty.c b/py/objproperty.c
index fb814cba1a..323696cf15 100644
--- a/py/objproperty.c
+++ b/py/objproperty.c
@@ -37,7 +37,7 @@ typedef struct _mp_obj_property_t {
     mp_obj_t proxy[3]; // getter, setter, deleter
 } mp_obj_property_t;
 
-STATIC mp_obj_t property_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
+STATIC mp_obj_t property_make_new(mp_obj_t type_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
     mp_arg_check_num(n_args, n_kw, 0, 4, false);
 
     mp_obj_property_t *o = m_new_obj(mp_obj_property_t);
diff --git a/py/objrange.c b/py/objrange.c
index 7a4aaa72cd..bec026ff6f 100644
--- a/py/objrange.c
+++ b/py/objrange.c
@@ -90,7 +90,7 @@ STATIC void range_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind
     }
 }
 
-STATIC mp_obj_t range_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
+STATIC mp_obj_t range_make_new(mp_obj_t type_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
     mp_arg_check_num(n_args, n_kw, 1, 3, false);
 
     mp_obj_range_t *o = m_new_obj(mp_obj_range_t);
diff --git a/py/objreversed.c b/py/objreversed.c
index 2b16f0893f..b0da00a885 100644
--- a/py/objreversed.c
+++ b/py/objreversed.c
@@ -38,7 +38,7 @@ typedef struct _mp_obj_reversed_t {
     mp_uint_t cur_index;    // current index, plus 1; 0=no more, 1=last one (index 0)
 } mp_obj_reversed_t;
 
-STATIC mp_obj_t reversed_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
+STATIC mp_obj_t reversed_make_new(mp_obj_t type_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
     mp_arg_check_num(n_args, n_kw, 1, 1, false);
 
     // check if __reversed__ exists, and if so delegate to it
diff --git a/py/objset.c b/py/objset.c
index fbcf0cdae9..6ac9c580ab 100644
--- a/py/objset.c
+++ b/py/objset.c
@@ -119,7 +119,7 @@ STATIC void set_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t
     #endif
 }
 
-STATIC mp_obj_t set_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
+STATIC mp_obj_t set_make_new(mp_obj_t type_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
     mp_arg_check_num(n_args, n_kw, 0, 1, false);
 
     switch (n_args) {
diff --git a/py/objstr.c b/py/objstr.c
index c4335bbac7..55c7cdd5f7 100644
--- a/py/objstr.c
+++ b/py/objstr.c
@@ -131,7 +131,7 @@ STATIC void str_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t
     }
 }
 
-mp_obj_t mp_obj_str_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
+mp_obj_t mp_obj_str_make_new(mp_obj_t type_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
 #if MICROPY_CPYTHON_COMPAT
     if (n_kw != 0) {
         mp_arg_error_unimpl_kw();
@@ -169,7 +169,7 @@ mp_obj_t mp_obj_str_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw,
     }
 }
 
-STATIC mp_obj_t bytes_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
+STATIC mp_obj_t bytes_make_new(mp_obj_t type_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
     (void)type_in;
 
     #if MICROPY_CPYTHON_COMPAT
diff --git a/py/objstr.h b/py/objstr.h
index d9cc85ef0b..d9327b1ab8 100644
--- a/py/objstr.h
+++ b/py/objstr.h
@@ -60,7 +60,7 @@ const byte *mp_obj_str_get_data_no_check(mp_obj_t self_in, size_t *len);
     else { str_len = ((mp_obj_str_t*)MP_OBJ_TO_PTR(str_obj_in))->len; str_data = ((mp_obj_str_t*)MP_OBJ_TO_PTR(str_obj_in))->data; }
 #endif
 
-mp_obj_t mp_obj_str_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args);
+mp_obj_t mp_obj_str_make_new(mp_obj_t type_in, size_t n_args, size_t n_kw, const mp_obj_t *args);
 void mp_str_print_json(const mp_print_t *print, const byte *str_data, size_t str_len);
 mp_obj_t mp_obj_str_format(mp_uint_t n_args, const mp_obj_t *args, mp_map_t *kwargs);
 mp_obj_t mp_obj_str_split(mp_uint_t n_args, const mp_obj_t *args);
diff --git a/py/objstringio.c b/py/objstringio.c
index 5a8f43da13..d046cdd80d 100644
--- a/py/objstringio.c
+++ b/py/objstringio.c
@@ -128,7 +128,7 @@ STATIC mp_obj_stringio_t *stringio_new(mp_obj_t type_in) {
     return o;
 }
 
-STATIC mp_obj_t stringio_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
+STATIC mp_obj_t stringio_make_new(mp_obj_t type_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
     (void)n_kw; // TODO check n_kw==0
     mp_obj_stringio_t *o = stringio_new(type_in);
 
diff --git a/py/objtuple.c b/py/objtuple.c
index de2bfc31d2..8337b67042 100644
--- a/py/objtuple.c
+++ b/py/objtuple.c
@@ -61,7 +61,7 @@ void mp_obj_tuple_print(const mp_print_t *print, mp_obj_t o_in, mp_print_kind_t
     }
 }
 
-STATIC mp_obj_t mp_obj_tuple_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
+STATIC mp_obj_t mp_obj_tuple_make_new(mp_obj_t type_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
     (void)type_in;
 
     mp_arg_check_num(n_args, n_kw, 0, 1, false);
diff --git a/py/objtype.c b/py/objtype.c
index ca52006f25..c9ab59642f 100644
--- a/py/objtype.c
+++ b/py/objtype.c
@@ -43,7 +43,7 @@
 #define DEBUG_printf(...) (void)0
 #endif
 
-STATIC mp_obj_t static_class_method_make_new(mp_obj_t self_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args);
+STATIC mp_obj_t static_class_method_make_new(mp_obj_t self_in, size_t n_args, size_t n_kw, const mp_obj_t *args);
 
 /******************************************************************************/
 // instance object
@@ -235,7 +235,7 @@ STATIC void instance_print(const mp_print_t *print, mp_obj_t self_in, mp_print_k
     mp_printf(print, "<%s object at %p>", mp_obj_get_type_str(self_in), self_in);
 }
 
-mp_obj_t mp_obj_instance_make_new(mp_obj_t self_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
+mp_obj_t mp_obj_instance_make_new(mp_obj_t self_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
     assert(MP_OBJ_IS_TYPE(self_in, &mp_type_type));
     mp_obj_type_t *self = MP_OBJ_TO_PTR(self_in);
     assert(mp_obj_is_instance_type(self));
@@ -707,7 +707,7 @@ bool mp_obj_instance_is_callable(mp_obj_t self_in) {
     return mp_obj_instance_get_call(self_in) != MP_OBJ_NULL;
 }
 
-mp_obj_t mp_obj_instance_call(mp_obj_t self_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
+mp_obj_t mp_obj_instance_call(mp_obj_t self_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
     mp_obj_t call = mp_obj_instance_get_call(self_in);
     if (call == MP_OBJ_NULL) {
         if (MICROPY_ERROR_REPORTING == MICROPY_ERROR_REPORTING_TERSE) {
@@ -778,7 +778,7 @@ STATIC void type_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_
     mp_printf(print, "<class '%q'>", self->name);
 }
 
-STATIC mp_obj_t type_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
+STATIC mp_obj_t type_make_new(mp_obj_t type_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
     (void)type_in;
 
     mp_arg_check_num(n_args, n_kw, 1, 3, false);
@@ -798,7 +798,7 @@ STATIC mp_obj_t type_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw
     }
 }
 
-STATIC mp_obj_t type_call(mp_obj_t self_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
+STATIC mp_obj_t type_call(mp_obj_t self_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
     // instantiate an instance of a class
 
     mp_obj_type_t *self = MP_OBJ_TO_PTR(self_in);
@@ -957,7 +957,7 @@ STATIC void super_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind
     mp_print_str(print, ">");
 }
 
-STATIC mp_obj_t super_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
+STATIC mp_obj_t super_make_new(mp_obj_t type_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
     (void)type_in;
     // 0 arguments are turned into 2 in the compiler
     // 1 argument is not yet implemented
@@ -1108,7 +1108,7 @@ mp_obj_t mp_instance_cast_to_native_base(mp_const_obj_t self_in, mp_const_obj_t
 /******************************************************************************/
 // staticmethod and classmethod types (probably should go in a different file)
 
-STATIC mp_obj_t static_class_method_make_new(mp_obj_t self_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
+STATIC mp_obj_t static_class_method_make_new(mp_obj_t self_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
     mp_obj_type_t *self = MP_OBJ_TO_PTR(self_in);
     assert(self == &mp_type_staticmethod || self == &mp_type_classmethod);
 
diff --git a/py/objtype.h b/py/objtype.h
index 6023e8dfe5..06227cf5a3 100644
--- a/py/objtype.h
+++ b/py/objtype.h
@@ -42,11 +42,11 @@ void mp_obj_instance_attr(mp_obj_t self_in, qstr attr, mp_obj_t *dest);
 
 // these need to be exposed so mp_obj_is_callable can work correctly
 bool mp_obj_instance_is_callable(mp_obj_t self_in);
-mp_obj_t mp_obj_instance_call(mp_obj_t self_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args);
+mp_obj_t mp_obj_instance_call(mp_obj_t self_in, size_t n_args, size_t n_kw, const mp_obj_t *args);
 
 #define mp_obj_is_instance_type(type) ((type)->make_new == mp_obj_instance_make_new)
 #define mp_obj_is_native_type(type) ((type)->make_new != mp_obj_instance_make_new)
 // this needs to be exposed for the above macros to work correctly
-mp_obj_t mp_obj_instance_make_new(mp_obj_t self_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args);
+mp_obj_t mp_obj_instance_make_new(mp_obj_t self_in, size_t n_args, size_t n_kw, const mp_obj_t *args);
 
 #endif // __MICROPY_INCLUDED_PY_OBJTYPE_H__
diff --git a/py/objzip.c b/py/objzip.c
index 3ac6af15cd..4b240fbbf7 100644
--- a/py/objzip.c
+++ b/py/objzip.c
@@ -36,7 +36,7 @@ typedef struct _mp_obj_zip_t {
     mp_obj_t iters[];
 } mp_obj_zip_t;
 
-STATIC mp_obj_t zip_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
+STATIC mp_obj_t zip_make_new(mp_obj_t type_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
     mp_arg_check_num(n_args, n_kw, 0, MP_OBJ_FUN_ARGS_MAX, false);
 
     mp_obj_zip_t *o = m_new_obj_var(mp_obj_zip_t, mp_obj_t, n_args);
diff --git a/py/runtime.c b/py/runtime.c
index c97710bc90..b0f407a150 100644
--- a/py/runtime.c
+++ b/py/runtime.c
@@ -894,7 +894,7 @@ typedef struct _mp_obj_checked_fun_t {
     mp_obj_t fun;
 } mp_obj_checked_fun_t;
 
-STATIC mp_obj_t checked_fun_call(mp_obj_t self_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
+STATIC mp_obj_t checked_fun_call(mp_obj_t self_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
     mp_obj_checked_fun_t *self = MP_OBJ_TO_PTR(self_in);
     if (n_args > 0) {
         const mp_obj_type_t *arg0_type = mp_obj_get_type(args[0]);
diff --git a/unix/file.c b/unix/file.c
index 7f113d6712..751d62fd51 100644
--- a/unix/file.c
+++ b/unix/file.c
@@ -202,7 +202,7 @@ 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(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
+STATIC mp_obj_t fdfile_make_new(mp_obj_t type_in, size_t n_args, size_t n_kw, const mp_obj_t *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);
     return fdfile_open(MP_OBJ_TO_PTR(type_in), arg_vals);
diff --git a/unix/modffi.c b/unix/modffi.c
index c998a809e4..be12974979 100644
--- a/unix/modffi.c
+++ b/unix/modffi.c
@@ -301,7 +301,7 @@ 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(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
+STATIC mp_obj_t ffimod_make_new(mp_obj_t type_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
     (void)n_args;
     (void)n_kw;
 
@@ -345,7 +345,7 @@ STATIC void ffifunc_print(const mp_print_t *print, mp_obj_t self_in, mp_print_ki
     mp_printf(print, "<ffifunc %p>", self->func);
 }
 
-STATIC mp_obj_t ffifunc_call(mp_obj_t self_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
+STATIC mp_obj_t ffifunc_call(mp_obj_t self_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
     mp_obj_ffifunc_t *self = MP_OBJ_TO_PTR(self_in);
     assert(n_kw == 0);
     assert(n_args == self->cif.nargs);
diff --git a/unix/modsocket.c b/unix/modsocket.c
index 6a7c3f5510..0857d05733 100644
--- a/unix/modsocket.c
+++ b/unix/modsocket.c
@@ -313,7 +313,7 @@ STATIC mp_obj_t socket_makefile(mp_uint_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(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
+STATIC mp_obj_t socket_make_new(mp_obj_t type_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
     (void)type_in;
     (void)n_kw;