Error on alias deployment using serverless-aws-alias plugin

Hey everyone,
I’m starting out with the serverless framework, really like it so far.
I was also really interested in using serverless-aws-alias plugin to make it work with multiple aliases (Dev / QA / Prod), and I was able to install the plugin without any problem and to do my first deployment successfully. But when I try to do a second deployment using an alias with serverless deploy --alias prod I get the following error :

An error occurred while provisioning your stack: ApiGatewayResourceTests
     - Another resource with the same parent already has this name: tests.

Would anyone have an idea of what’s causing this ?
If I’m not in the right place to ask please let me know !