Updating S3 bucket deletes bucket contents

Serverless Framework
1

I have a lambda that gets input from an S3 bucket. I’ve created the bucket and an attached bucket policy in my Resources section, however whenever I deploy it deletes the existing contents of my bucket. Is this intentional? Does anyone know if there is a work-around for this?

S3BucketMyBucket: 
   Type: AWS::S3::Bucket
   Properties:
     BucketName: my-bucket
devMyBucketPolicy:
  Type: AWS::S3::BucketPolicy
  Properties:
    Bucket: my-bucket
    PolicyDocument:
      Version: "2012-10-17"
      Statement:
        -
          Effect: Allow
          Principal:
            Service:
              - ses.amazonaws.com
          Action: s3:PutObject
          Resource:
            - arn:aws:s3:::my-bucket/*
          Condition:
            StringEquals:
              aws:Referer:
                - 1111111111111
2

It depends what you changed. Serverless uses CloudFormation so you can always look at the CloudFormation documents to see if changing a property will require the bucket to be replaced.