diff --git a/docker-entrypoint.sh b/docker-entrypoint.sh
index adf9eaa098..c34a8df80a 100755
--- a/docker-entrypoint.sh
+++ b/docker-entrypoint.sh
@@ -2,7 +2,13 @@
 set -e
 
 if [ -n "$MYSQL_PORT_3306_TCP" ]; then
-	WORDPRESS_DB_HOST='mysql'
+	if [ -z "$WORDPRESS_DB_HOST" ]; then
+		WORDPRESS_DB_HOST='mysql'
+	else
+		echo >&2 'warning: both WORDPRESS_DB_HOST and MYSQL_PORT_3306_TCP found'
+		echo >&2 "  Connecting to WORDPRESS_DB_HOST ($WORDPRESS_DB_HOST)"
+		echo >&2 '  instead of the linked mysql container'
+	fi
 fi
 
 if [ -z "$WORDPRESS_DB_HOST" ]; then