Escape = sign in environment variable

Hi guys, I’m new here. I came across a problem while trying to deploy my lambda function to aws using
serverless deploy:

serverless deploy --var="123=321"

The problem is the environment variable var gets the value “123” instead of “123=321”. It’s chopped up at the “=” sign. How can I escape the = sign in this situation? I tried surround the value with single quotes, double quotes. It doesn’t work.

The output:
Serverless: *****
{ var: ‘123’ }