CloudFront Function

Hi,
I'm trying to create a CloudFormation stack that deploys a CloudFront Function.
The specific code is:

AWSTemplateFormatVersion: "2010-09-09"
Description: CloudFront Test Function
Resources:
  ResponseFunction:
    Type: 'AWS::CloudFront::Function'
    Properties:
      Name: !Sub '${AWS::StackName}-response'
      AutoPublish: true
      FunctionCode: |
        function handler(event) {
            var response = event.response;
            var headers = response.headers;
            headers\['strict-transport-security'] = {value: 'max-age=63072000; includeSubDomains; preload'};
            headers\['content-security-policy'] = {value: "default-src 'none';"};
            headers\['x-content-type-options'] = {value: 'nosniff'};
            headers\['x-frame-options'] = {value: 'DENY'};
            headers\['x-xss-protection'] = {value: '1; mode=block'};
            headers\['referrer-policy'] = {value: 'same-origin'};
            return response;
        }

Trying to deploy it fails with a not-useful error:
Resource handler returned message: "null" (RequestToken: 278d458f-5016-4b68-f156-2eee41d00f94, HandlerErrorCode: InternalFailure)

Has anyone any idea on the issue or how to fix it?

Thanks a lot,
Fale

Edited by: Fale on Jun 4, 2021 2:40 AM