Cannot drop database in postgres

I would like to unserstand why I am not able to drop a database from cmd: I execute the command: drop database if exists but the result is as below: postgres=# drop database testV5; ERROR: database "testV5" does not exist knowing that the database exists: postgres=# \l Liste des bases de donnÚes Nom | PropriÚtaire | Encodage | Collationnement | Type caract. | Droits d'accÞs testV4 | postgres | UTF8 | French_Canada.1252 | French_Canada.1252 | testV5 | postgres | UTF8 | French_Canada.1252 | French_Canada.1252 | postgres | postgres | UTF8 | French_Canada.1252 | French_Canada.1252 | template0| postgres | UTF8 | French_Canada.1252 | French_Canada.1252 | template1| postgres | UTF8 | French_Canada.1252 | French_Canada.1252 | Can anyone explain that please ? Thanks in advance.