diff --git a/docker-compose.yml b/docker-compose.yml
index 81a66da..3da75eb 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -1,5 +1,5 @@
 
-version: '2'
+version: '3'
 
 services:
   pg-master:
@@ -14,6 +14,8 @@ services:
      - '/var/lib/postgresql/data'
     expose:
      - '5432'
+    networks:
+     - pg-replication
 
   pg-slave:
     build: '.'
@@ -28,5 +30,8 @@ services:
      - '/var/lib/postgresql/data'
     expose:
      - '5432'
-    links:
-     - 'pg-master'
+    networks:
+     - pg-replication
+networks:
+  pg-replication:
+    external: true