diff --git a/packages/env/lib/build-docker-compose-config.js b/packages/env/lib/build-docker-compose-config.js
index 668836de88878..b17cb7bb58212 100644
--- a/packages/env/lib/build-docker-compose-config.js
+++ b/packages/env/lib/build-docker-compose-config.js
@@ -9,6 +9,7 @@ const path = require( 'path' );
  * Internal dependencies
  */
 const { hasSameCoreSource } = require( './wordpress' );
+const { dbEnv } = require( './config' );
 
 /**
  * @typedef {import('./config').WPConfig} WPConfig
@@ -176,26 +177,40 @@ module.exports = function buildDockerComposeConfig( config ) {
 				image: 'mariadb',
 				ports: [ '3306' ],
 				environment: {
-					MYSQL_ALLOW_EMPTY_PASSWORD: 'yes',
+					MYSQL_ROOT_PASSWORD:
+						dbEnv.credentials.WORDPRESS_DB_PASSWORD,
+					MYSQL_DATABASE: dbEnv.development.WORDPRESS_DB_NAME,
 				},
 				volumes: [ 'mysql:/var/lib/mysql' ],
 			},
+			'tests-mysql': {
+				image: 'mariadb',
+				ports: [ '3306' ],
+				environment: {
+					MYSQL_ROOT_PASSWORD:
+						dbEnv.credentials.WORDPRESS_DB_PASSWORD,
+					MYSQL_DATABASE: dbEnv.tests.WORDPRESS_DB_NAME,
+				},
+				volumes: [ 'mysql-test:/var/lib/mysql' ],
+			},
 			wordpress: {
 				build: '.',
 				depends_on: [ 'mysql' ],
 				image: developmentWpImage,
 				ports: [ developmentPorts ],
 				environment: {
-					WORDPRESS_DB_NAME: 'wordpress',
+					...dbEnv.credentials,
+					...dbEnv.development,
 				},
 				volumes: developmentMounts,
 			},
 			'tests-wordpress': {
-				depends_on: [ 'mysql' ],
+				depends_on: [ 'tests-mysql' ],
 				image: testsWpImage,
 				ports: [ testsPorts ],
 				environment: {
-					WORDPRESS_DB_NAME: 'tests-wordpress',
+					...dbEnv.credentials,
+					...dbEnv.tests,
 				},
 				volumes: testsMounts,
 			},
@@ -204,12 +219,20 @@ module.exports = function buildDockerComposeConfig( config ) {
 				image: developmentWpCliImage,
 				volumes: developmentMounts,
 				user: cliUser,
+				environment: {
+					...dbEnv.credentials,
+					...dbEnv.development,
+				},
 			},
 			'tests-cli': {
 				depends_on: [ 'tests-wordpress' ],
 				image: testsWpCliImage,
 				volumes: testsMounts,
 				user: cliUser,
+				environment: {
+					...dbEnv.credentials,
+					...dbEnv.tests,
+				},
 			},
 			composer: {
 				image: 'composer',
@@ -228,6 +251,8 @@ module.exports = function buildDockerComposeConfig( config ) {
 					LOCAL_DIR: 'html',
 					WP_PHPUNIT__TESTS_CONFIG:
 						'/var/www/html/phpunit-wp-config.php',
+					...dbEnv.credentials,
+					...dbEnv.tests,
 				},
 			},
 		},
@@ -235,6 +260,7 @@ module.exports = function buildDockerComposeConfig( config ) {
 			...( ! config.coreSource && { wordpress: {} } ),
 			...( ! config.coreSource && { 'tests-wordpress': {} } ),
 			mysql: {},
+			'mysql-test': {},
 			'phpunit-uploads': {},
 		},
 	};
diff --git a/packages/env/lib/commands/start.js b/packages/env/lib/commands/start.js
index 22fe075948c4a..4f3a00cc927dd 100644
--- a/packages/env/lib/commands/start.js
+++ b/packages/env/lib/commands/start.js
@@ -24,6 +24,7 @@ const downloadSources = require( '../download-sources' );
 const {
 	checkDatabaseConnection,
 	makeContentDirectoriesWritable,
+	makeConfigWritable,
 	configureWordPress,
 	setupWordPressDirectories,
 } = require( '../wordpress' );
@@ -140,6 +141,11 @@ module.exports = async function start( { spinner, debug, update, xdebug } ) {
 			: [],
 	} );
 
+	await Promise.all( [
+		makeConfigWritable( 'development', config ),
+		makeConfigWritable( 'tests', config ),
+	] );
+
 	// Only run WordPress install/configuration when config has changed.
 	if ( shouldConfigureWp ) {
 		spinner.text = 'Configuring WordPress.';
diff --git a/packages/env/lib/config/db-env.js b/packages/env/lib/config/db-env.js
new file mode 100644
index 0000000000000..6f06ff9731510
--- /dev/null
+++ b/packages/env/lib/config/db-env.js
@@ -0,0 +1,23 @@
+// Username and password used in all databases
+const credentials = {
+	WORDPRESS_DB_USER: 'root',
+	WORDPRESS_DB_PASSWORD: 'password',
+};
+
+// Environment for test database
+const tests = {
+	WORDPRESS_DB_NAME: 'tests-wordpress',
+	WORDPRESS_DB_HOST: 'tests-mysql',
+};
+
+// Environment for development database. DB host gets default value which is set
+// elsewhere
+const development = {
+	WORDPRESS_DB_NAME: 'wordpress',
+};
+
+module.exports = {
+	credentials,
+	tests,
+	development,
+};
diff --git a/packages/env/lib/config/index.js b/packages/env/lib/config/index.js
index 0dbbcc08a5b8a..1a944f43501d0 100644
--- a/packages/env/lib/config/index.js
+++ b/packages/env/lib/config/index.js
@@ -3,6 +3,7 @@
  */
 const readConfig = require( './config' );
 const { ValidationError } = require( './validate-config' );
+const dbEnv = require( './db-env' );
 
 /**
  * @typedef {import('./config').WPConfig} WPConfig
@@ -13,4 +14,5 @@ const { ValidationError } = require( './validate-config' );
 module.exports = {
 	ValidationError,
 	readConfig,
+	dbEnv,
 };
diff --git a/packages/env/lib/wordpress.js b/packages/env/lib/wordpress.js
index 07705167ac1dc..da632f9703b5b 100644
--- a/packages/env/lib/wordpress.js
+++ b/packages/env/lib/wordpress.js
@@ -47,6 +47,27 @@ async function makeContentDirectoriesWritable(
 	);
 }
 
+/**
+ * Makes wp-config.php owned by www-data so that WordPress can work with the
+ * file.
+ *
+ * @param {WPEnvironment} environment The environment to check. Either 'development' or 'tests'.
+ * @param {WPConfig}      config      The wp-env config object.
+ */
+async function makeConfigWritable(
+	environment,
+	{ dockerComposeConfigPath, debug }
+) {
+	await dockerCompose.exec(
+		environment === 'development' ? 'wordpress' : 'tests-wordpress',
+		'chown www-data:www-data wp-config.php',
+		{
+			config: dockerComposeConfigPath,
+			log: debug,
+		}
+	);
+}
+
 /**
  * Checks a WordPress database connection. An error is thrown if the test is
  * unsuccessful.
@@ -260,6 +281,7 @@ async function copyCoreFiles( fromPath, toPath ) {
 module.exports = {
 	hasSameCoreSource,
 	makeContentDirectoriesWritable,
+	makeConfigWritable,
 	checkDatabaseConnection,
 	configureWordPress,
 	resetDatabase,