# Using has\_type(list(Type), X) with user created type not working as expected **URL:** \ **Category:** Help!\ **Created:** [October 1, 2019, 5:38pm UTC](https://swi-prolog.discourse.group/t/using-has-type-list-type-x-with-user-created-type-not-working-as-expected/1340 "2019-10-01T17:38:25Z")\ **Posts on this page:** 1\ **Showing post:** 7
**Author:** ![jan](https://yyz2.discourse-cdn.com/free1/user_avatar/swi-prolog.discourse.group/jan/32/4_2.png) [@jan](https://swi-prolog.discourse.group/u/jan)\ **Post date:** [October 2, 2019, 10:00am UTC](https://swi-prolog.discourse.group/t/using-has-type-list-type-x-with-user-created-type-not-working-as-expected/1340/7 "2019-10-02T10:00:47Z")
The issue seems to be ```prolog :- begin_tests(example_bad). test(1) :- has_type(list(key_value),[kv(1,a),kv(2,b)]). :- end_tests(example_bad). ``` error:has\_type/2 is multifile, but not part of the interface of library(error). Type checking is done using must\_be/2 (throws error) or is\_of\_type/2 (fails) ```prolog :- begin_tests(example_bad). test(1) :- is_of_type(list(key_value),[kv(1,a),kv(2,b)]). :- end_tests(example_bad). ``` With that change I get ```prolog 101 ?- run_tests. % PL-Unit: example_bad . done % test passed true. ``` --- _[View the full topic](https://swi-prolog.discourse.group/t/using-has-type-list-type-x-with-user-created-type-not-working-as-expected/1340)._