diff --git a/py/objgenerator.c b/py/objgenerator.c
index a98de2cb972a6f4f9ec4e254952e53f448d5f4c1..7eaeac9cce92fbafdf6001d8862469bdfbdc2bb1 100644
--- a/py/objgenerator.c
+++ b/py/objgenerator.c
@@ -46,14 +46,37 @@ typedef struct _mp_obj_gen_wrap_t {
     mp_obj_t *fun;
 } mp_obj_gen_wrap_t;
 
-mp_obj_t mp_obj_new_gen_instance(mp_obj_fun_bc_t *self_fun, uint n_args, uint n_kw, const mp_obj_t *args);
+typedef struct _mp_obj_gen_instance_t {
+    mp_obj_base_t base;
+    mp_obj_dict_t *globals;
+    mp_code_state code_state;
+} mp_obj_gen_instance_t;
 
 STATIC mp_obj_t gen_wrap_call(mp_obj_t self_in, uint n_args, uint n_kw, const mp_obj_t *args) {
     mp_obj_gen_wrap_t *self = self_in;
     mp_obj_fun_bc_t *self_fun = (mp_obj_fun_bc_t*)self->fun;
     assert(MP_OBJ_IS_TYPE(self_fun, &mp_type_fun_bc));
 
-    return mp_obj_new_gen_instance(self_fun, n_args, n_kw, args);
+    const byte *bytecode = self_fun->bytecode;
+    // get code info size, and skip the line number table
+    machine_uint_t code_info_size = bytecode[0] | (bytecode[1] << 8) | (bytecode[2] << 16) | (bytecode[3] << 24);
+    bytecode += code_info_size;
+
+    // bytecode prelude: get state size and exception stack size
+    machine_uint_t n_state = bytecode[0] | (bytecode[1] << 8);
+    machine_uint_t n_exc_stack = bytecode[2] | (bytecode[3] << 8);
+    bytecode += 4;
+
+    // allocate the generator object, with room for local stack and exception stack
+    mp_obj_gen_instance_t *o = m_new_obj_var(mp_obj_gen_instance_t, byte,
+        n_state * sizeof(mp_obj_t) + n_exc_stack * sizeof(mp_exc_stack_t));
+    o->base.type = &mp_type_gen_instance;
+
+    o->globals = self_fun->globals;
+    o->code_state.n_state = n_state;
+    o->code_state.ip = bytecode;
+    mp_setup_code_state(&o->code_state, self_fun, n_args, n_kw, args);
+    return o;
 }
 
 const mp_obj_type_t mp_type_gen_wrap = {
@@ -72,12 +95,6 @@ mp_obj_t mp_obj_new_gen_wrap(mp_obj_t fun) {
 /******************************************************************************/
 /* generator instance                                                         */
 
-typedef struct _mp_obj_gen_instance_t {
-    mp_obj_base_t base;
-    mp_obj_dict_t *globals;
-    mp_code_state code_state;
-} mp_obj_gen_instance_t;
-
 void gen_instance_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t self_in, mp_print_kind_t kind) {
     mp_obj_gen_instance_t *self = self_in;
     print(env, "<generator object '%s' at %p>", mp_obj_code_get_name(self->code_state.code_info), self_in);
@@ -233,26 +250,3 @@ const mp_obj_type_t mp_type_gen_instance = {
     .iternext = gen_instance_iternext,
     .locals_dict = (mp_obj_t)&gen_instance_locals_dict,
 };
-
-mp_obj_t mp_obj_new_gen_instance(mp_obj_fun_bc_t *self_fun, uint n_args, uint n_kw, const mp_obj_t *args) {
-    const byte *bytecode = self_fun->bytecode;
-    // get code info size, and skip the line number table
-    machine_uint_t code_info_size = bytecode[0] | (bytecode[1] << 8) | (bytecode[2] << 16) | (bytecode[3] << 24);
-    bytecode += code_info_size;
-
-    // bytecode prelude: get state size and exception stack size
-    machine_uint_t n_state = bytecode[0] | (bytecode[1] << 8);
-    machine_uint_t n_exc_stack = bytecode[2] | (bytecode[3] << 8);
-    bytecode += 4;
-
-    // allocate the generator object, with room for local stack and exception stack
-    mp_obj_gen_instance_t *o = m_new_obj_var(mp_obj_gen_instance_t, byte, n_state * sizeof(mp_obj_t) + n_exc_stack * sizeof(mp_exc_stack_t));
-    o->base.type = &mp_type_gen_instance;
-    o->globals = self_fun->globals;
-
-    o->code_state.n_state = n_state;
-    o->code_state.ip = bytecode;
-    mp_setup_code_state(&o->code_state, self_fun, n_args, n_kw, args);
-
-    return o;
-}