The present disclosure concerns a process for converting alkyl halides to ethylene and propylene, said process comprising the steps of (a) providing a feedstream comprising alkyl halides; (b) providing a first and second catalyst composition, said second catalyst composition comprising a cracking catalyst; (c) contacting said feedstream with said first catalyst composition in a first reaction zone under first reaction conditions to provide a first product stream, and (d) subjecting at least a part of said first product stream to an Olefin Catalytic Cracking with said second catalyst composition in a second reaction zone under second reaction conditions to provide a second product steam. The process is remarkable in that it further comprises a step of steaming said first catalyst composition before the step (c) and in that said first catalyst composition comprises zeolites and a binder, wherein said zeolites comprise at least one 10-membered ring channel.