Yaml scanner scannererror while scanning a simple key

I get the following error from docker-compose:

docker-compose up -d ERROR: yaml.scanner.ScannerError: while scanning a simple key in "./docker-compose.yml", line 4, column 1 could not find expected ':' in "./docker-compose.yml", line 5, column 1

This is my docker-compose.yaml:

version: '2.0' services: #PHP Service app: build: context: . dockerfile: Dockerfile image: cloudsigma.com/php container_name: app restart: unless-stopped tty: true environment: SERVICE_NAME: app SERVICE_TAGS: dev working_dir: /var/www/html/ volumes: - ./:/var/www/html/ - ./php/laravel.ini:/usr/local/etc/php/conf.d/laravel.ini networks: - app-network

Can somebody tell me what is wrong with my compose file?