diff --git a/py/obj.h b/py/obj.h
index b5b855bad3..cb9a6cc459 100644
--- a/py/obj.h
+++ b/py/obj.h
@@ -773,15 +773,14 @@ typedef struct _mp_obj_full_type_t {
 // of the 29th argument (29 is 13*2 + 3).
 #define MP_DEFINE_CONST_OBJ_TYPE_NARGS(_1, _2, _3, _4, _5, _6, _7, _8, _9, _10, _11, _12, _13, _14, _15, _16, _17, _18, _19, _20, _21, _22, _23, _24, _25, _26, _27, _28, N, ...) MP_DEFINE_CONST_OBJ_TYPE_NARGS_##N
 
-// These macros are used to define a object type in ROM.
+// This macros is used to define a object type in ROM.
 // Invoke as MP_DEFINE_CONST_OBJ_TYPE(_typename, _name, _flags, _make_new [, slot, func]*)
-// They use the number of arguments to select which MP_DEFINE_CONST_OBJ_TYPE_*
+// It uses the number of arguments to select which MP_DEFINE_CONST_OBJ_TYPE_*
 // macro to use based on the number of arguments. It works by shifting the
 // numeric values 12, 11, ... 0 by the number of arguments, such that the
 // 29th argument ends up being the number to use. The _INV values are
 // placeholders because the slot arguments come in pairs.
 #define MP_DEFINE_CONST_OBJ_TYPE(...) MP_DEFINE_CONST_OBJ_TYPE_EXPAND(MP_DEFINE_CONST_OBJ_TYPE_NARGS(__VA_ARGS__, _INV, 12, _INV, 11, _INV, 10, _INV, 9, _INV, 8, _INV, 7, _INV, 6, _INV, 5, _INV, 4, _INV, 3, _INV, 2, _INV, 1, _INV, 0)(mp_obj_type_t, __VA_ARGS__))
-#define MP_DEFINE_CONST_OBJ_FULL_TYPE(...) MP_DEFINE_CONST_OBJ_TYPE_EXPAND(MP_DEFINE_CONST_OBJ_TYPE_NARGS(__VA_ARGS__, _INV, 12, _INV, 11, _INV, 10, _INV, 9, _INV, 8, _INV, 7, _INV, 6, _INV, 5, _INV, 4, _INV, 3, _INV, 2, _INV, 1, _INV, 0)(mp_obj_full_type_t, __VA_ARGS__))
 
 // Constant types, globally accessible
 extern const mp_obj_type_t mp_type_type;