Index: .env
===================================================================
--- .env	(revision 49835)
+++ .env	(working copy)
@@ -45,8 +45,18 @@
 # Whether or not to enable Memcached.
 LOCAL_PHP_MEMCACHED=false
 
-# The MySQL version to use. See https://hub.docker.com/_/mysql/ for valid versions.
-LOCAL_MYSQL=5.7
+# The database software to use.
+#
+# Supported values are `mysql` and `mariadb`.
+LOCAL_DB_TYPE=mysql
+
+# The database version to use.
+#
+# Defaults to 5.7 with the assumption that LOCAL_DB_TYPE is set to `mysql` above.
+#
+# When using `mysql`, see https://hub.docker.com/_/mysql/ for valid versions.
+# When using `mariadb`, see https://hub.docker.com/_/mariadb for valid versions.
+LOCAL_DB_VERSION=5.7
 
 # The debug settings to add to `wp-config.php`.
 LOCAL_WP_DEBUG=true
Index: docker-compose.yml
===================================================================
--- docker-compose.yml	(revision 49835)
+++ docker-compose.yml	(working copy)
@@ -53,7 +53,7 @@
   # The MySQL container.
   ##
   mysql:
-    image: mysql:${LOCAL_MYSQL-latest}
+    image: ${LOCAL_DB_TYPE-mysql}:${LOCAL_DB_VERSION-latest}
 
     networks:
       - wpdevnet