diff --git a/README.md b/README.md
index d34499f..8385e9c 100644
--- a/README.md
+++ b/README.md
@@ -9,6 +9,7 @@
     mailcow_storage_dir: "/mnt/juice/mailcow"
     mailcow_local_http_port: "9001"
     mailcow_timezone: "Europe/Warsaw"
+	mailcow_docker_subnet=172.30.1
   roles:
     - mailcow
 ```
diff --git a/tasks/main.yml b/tasks/main.yml
index 66c1a70..7634180 100644
--- a/tasks/main.yml
+++ b/tasks/main.yml
@@ -82,6 +82,12 @@
     chdir: "{{ mailcow_repo_dir }}"
     creates: "{{ mailcow_repo_dir }}/mailcow.conf"
 
+- name: Configure Mailcow IPv4 network
+  ansible.builtin.lineinfile:
+    path: "{{ mailcow_repo_dir }}/mailcow.conf"
+    regexp: "^IPV4_NETWORK="
+    line: "IPV4_NETWORK={{ mailcow_docker_subnet }}"
+
 - name: "Disable mailcow letsencrypt"
   lineinfile:
     path: "{{ mailcow_repo_dir }}/mailcow.conf"