{
	"name": "silverstripe/dynamodb",
	"description": "SilverStripe DynamoDB integration.",
	"type": "silverstripe-vendormodule",
	"keywords": ["silverstripe", "aws", "dynamodb"],
	"license": "BSD-3-Clause",
	"authors": [
		{
			"name": "SilverStripe",
			"homepage": "http://silverstripe.com"
		},
		{
			"name": "The SilverStripe Community",
			"homepage": "http://silverstripe.org"
		}
	],
	"require": {
		"aws/aws-sdk-php": "~3.18",
		"doctrine/cache": "1.*",
		"silverstripe/crontask": "*",
		"silverstripe/framework": "^4@dev"
	},
	"require-dev": {
		"phpunit/PHPUnit": "^5.7"
	},
	"autoload": {
    "psr-4": {
      "SilverStripe\\DynamoDb\\": "code/",
      "SilverStripe\\DynamoDb\\Tests\\": "tests/"
    }
  },
	"extra": {
		"installer-name": "silverstripe-dynamodb",
		"branch-alias": {
			"dev-master": "3.0.x-dev"
		}
	},
	"scripts": {
		"lint": "phpcs code/ tests/"
	},
	"minimum-stability": "dev",
	"prefer-stable": true
}

{
	"name": "silverstripe/dynamodb",
	"description": "SilverStripe DynamoDB integration.",
	"type": "silverstripe-vendormodule",
	"keywords": ["silverstripe", "aws", "dynamodb"],
	"license": "BSD-3-Clause",
	"authors": [
		{
			"name": "SilverStripe",
			"homepage": "http://silverstripe.com"
		},
		{
			"name": "The SilverStripe Community",
			"homepage": "http://silverstripe.org"
		}
	],
	"require": {
		"aws/aws-sdk-php": "~3.18",
		"doctrine/cache": "1.*",
		"silverstripe/crontask": "*",
		"silverstripe/framework": "^4@dev"
	},
	"require-dev": {
		"phpunit/PHPUnit": "^5.7"
	},
	"autoload": {
    "psr-4": {
      "SilverStripe\\DynamoDb\\": "code/",
      "SilverStripe\\DynamoDb\\Tests\\": "tests/"
    }
  },
	"extra": {
		"installer-name": "silverstripe-dynamodb",
		"branch-alias": {
			"dev-master": "4.0.x-dev"
		}
	},
	"scripts": {
		"lint": "phpcs code/ tests/"
	},
	"minimum-stability": "dev",
	"prefer-stable": true
}

Correct branch alias to 4.x-dev
Correct branch alias to 4.x-dev

master was tagged with 5983c4877b9d4518427e18685aff45cc9b136f6c on master already. The current state means you'll get a *newer* checkout with `composer require silverstripe/dynamodb:3.x-dev` than with `composer require silverstripe/dynamodb:^4`
