Select COUNT in COQL

Select COUNT in COQL

Hello,
I would like to execute a COQL query using a COUNT like this :

SELECT COUNT(*) as Nbr, Last_Name, First_Name
FROM Contacts 
WHERE 
(Last_Name like 'MY_NAME')
GROUP BY Last_Name, First_Name
HAVING Nbr > 1

But the result is :
{ ["clause"]=> string(8) "group by" ["column_name"]=> string(8) "COUNT(*)" } ["message"]=> string(48) "select column should be given in group by clause" ["status"]=> string(5) "error" }

Is there a solution to obtain this count ?
Tank you.