diff --git a/py/runtime.h b/py/runtime.h
index f81a6263d0..06e68924b2 100644
--- a/py/runtime.h
+++ b/py/runtime.h
@@ -133,12 +133,11 @@ mp_obj_t mp_import_name(qstr name, mp_obj_t fromlist, mp_obj_t level);
 mp_obj_t mp_import_from(mp_obj_t module, qstr name);
 void mp_import_all(mp_obj_t module);
 
-// Raise NotImplementedError with given message
 NORETURN void mp_raise_msg(const mp_obj_type_t *exc_type, const char *msg);
 //NORETURN void nlr_raise_msg_varg(const mp_obj_type_t *exc_type, const char *fmt, ...);
 NORETURN void mp_raise_ValueError(const char *msg);
 NORETURN void mp_raise_TypeError(const char *msg);
-NORETURN void mp_not_implemented(const char *msg);
+NORETURN void mp_not_implemented(const char *msg); // Raise NotImplementedError with given message
 NORETURN void mp_exc_recursion_depth(void);
 
 #if MICROPY_BUILTIN_METHOD_CHECK_SELF_ARG