Index: .env
===================================================================
--- .env	(revision 49549)
+++ .env	(working copy)
@@ -45,6 +45,9 @@
 # Whether or not to enable Memcached.
 LOCAL_PHP_MEMCACHED=false
 
+# The database software to use. Supported values are `mysql` and ``mariadb`.
+LOCAL_DB_TYPE=mysql
+
 # The MySQL version to use. See https://hub.docker.com/_/mysql/ for valid versions.
 LOCAL_MYSQL=5.7
 
Index: docker-compose.yml
===================================================================
--- docker-compose.yml	(revision 49549)
+++ docker-compose.yml	(working copy)
@@ -53,7 +53,7 @@
   # The MySQL container.
   ##
   mysql:
-    image: mysql:${LOCAL_MYSQL-latest}
+    image: ${LOCAL_DB_TYPE-mysql}:${LOCAL_MYSQL-latest}
 
     networks:
       - wpdevnet