default operator class (PostgreSQL's error?)

I create a scalar type name_t. Then I define the operator class for
it:

create operator class name_ops
default for type name_t
using btree as
operator 1 <,
operator 2 <=,
operator 3 =,
operator 4 >=,
operator 5 >,
function 1 name_cmp (name_t,name_t);

And it is DEFAULT for the type. Then I create some table:

create table name_l (
name name_t
unique
not null,
key smallint
primary key,
sex sex
);

And the UNIQUE constraint leads to the next error:

ERROR: data type name_t has no default operator class for access method "btree"
You must specify an operator class for the index or define a
default operator class for the data type

(There is no (of course?) such an error if I not use the UNIQUE
constraint). So, does this mean that it's an error in PostreSQL or it
is my fail thru some way?

Thanks in advance.