diff --git a/.github/workflows/deploy.yml b/.github/workflows/deploy.yml
index c8762ee..695a92a 100644
--- a/.github/workflows/deploy.yml
+++ b/.github/workflows/deploy.yml
@@ -125,6 +125,9 @@ jobs:
           DB_UPDATE_URL: ${{ secrets.DB_UPDATE_URL }}
           ORIGIN_CERT: ${{ secrets.ORIGIN_CERT }}
           ORIGIN_KEY: ${{ secrets.ORIGIN_KEY }}
+          IPV4_DOMAIN: ${{ secrets.IPV4_DOMAIN }}
+          IPV4_ORIGIN_CERT: ${{ secrets.IPV4_ORIGIN_CERT }}
+          IPV4_ORIGIN_KEY: ${{ secrets.IPV4_ORIGIN_KEY }}
           DOCKERHUB_TOKEN: ${{ secrets.DOCKERHUB_TOKEN }}
           DOCKERHUB_USERNAME: ${{ secrets.DOCKERHUB_USERNAME }}
           FIRST_DEPLOY: ${{ steps.detect.outputs.first_deploy }}
diff --git a/deploy/ansible/playbook.yml b/deploy/ansible/playbook.yml
index 63e16e0..afce703 100644
--- a/deploy/ansible/playbook.yml
+++ b/deploy/ansible/playbook.yml
@@ -10,6 +10,9 @@
     db_update_url: "{{ lookup('env', 'DB_UPDATE_URL') }}"
     origin_cert: "{{ lookup('env', 'ORIGIN_CERT') }}"
     origin_key: "{{ lookup('env', 'ORIGIN_KEY') }}"
+    ipv4_domain: "{{ lookup('env', 'IPV4_DOMAIN') | default('', true) }}"
+    ipv4_origin_cert: "{{ lookup('env', 'IPV4_ORIGIN_CERT') | default('', true) }}"
+    ipv4_origin_key: "{{ lookup('env', 'IPV4_ORIGIN_KEY') | default('', true) }}"
     dockerhub_token: "{{ lookup('env', 'DOCKERHUB_TOKEN') }}"
     dockerhub_username: "{{ lookup('env', 'DOCKERHUB_USERNAME') }}"
     first_deploy: "{{ lookup('env', 'FIRST_DEPLOY') | default('false', true) }}"
diff --git a/deploy/ansible/roles/app/tasks/main.yml b/deploy/ansible/roles/app/tasks/main.yml
index 9f51353..ccbd99e 100644
--- a/deploy/ansible/roles/app/tasks/main.yml
+++ b/deploy/ansible/roles/app/tasks/main.yml
@@ -32,6 +32,44 @@
     mode: "0644"
   notify: Reload haproxy
 
+- name: Create IPv4 domain TLS certificate directory
+  ansible.builtin.file:
+    path: /opt/rustyip/haproxy/certs-ipv4
+    state: directory
+    owner: root
+    group: root
+    mode: "0755"
+  when: ipv4_domain | length > 0
+
+- name: Deploy IPv4 domain TLS origin certificate
+  ansible.builtin.copy:
+    content: "{{ ipv4_origin_cert }}\n{{ ipv4_origin_key }}"
+    dest: /opt/rustyip/haproxy/certs-ipv4/origin.pem
+    owner: root
+    group: root
+    mode: "0644"
+  notify: Reload haproxy
+  when: ipv4_domain | length > 0
+
+- name: Deploy IPv4 domain list for HAProxy
+  ansible.builtin.copy:
+    content: "{{ ipv4_domain }}\n"
+    dest: /opt/rustyip/haproxy/ipv4_domain.lst
+    owner: root
+    group: root
+    mode: "0644"
+  when: ipv4_domain | length > 0
+  notify: Reload haproxy
+
+- name: Deploy empty IPv4 domain list when not configured
+  ansible.builtin.copy:
+    content: "# IPv4-only domain not configured\n"
+    dest: /opt/rustyip/haproxy/ipv4_domain.lst
+    owner: root
+    group: root
+    mode: "0644"
+  when: ipv4_domain | length == 0
+
 - name: Deploy environment file
   ansible.builtin.template:
     src: env.j2
diff --git a/deploy/ansible/roles/app/templates/docker-compose.yml.j2 b/deploy/ansible/roles/app/templates/docker-compose.yml.j2
index 23f50eb..f69cedf 100644
--- a/deploy/ansible/roles/app/templates/docker-compose.yml.j2
+++ b/deploy/ansible/roles/app/templates/docker-compose.yml.j2
@@ -7,7 +7,11 @@ services:
       - "443:443"
     volumes:
       - ./haproxy/haproxy.cfg:/usr/local/etc/haproxy/haproxy.cfg:ro
+      - ./haproxy/ipv4_domain.lst:/usr/local/etc/haproxy/ipv4_domain.lst:ro
       - ./haproxy/certs:/etc/haproxy/certs:ro
+{% if ipv4_domain %}
+      - ./haproxy/certs-ipv4:/etc/haproxy/certs-ipv4:ro
+{% endif %}
     restart: unless-stopped
     ulimits:
       nofile:
diff --git a/deploy/ansible/roles/app/templates/env.j2 b/deploy/ansible/roles/app/templates/env.j2
index 8cbcf83..4d154f9 100644
--- a/deploy/ansible/roles/app/templates/env.j2
+++ b/deploy/ansible/roles/app/templates/env.j2
@@ -3,3 +3,6 @@ DB_PATH=/data/Merged-IP.mmdb
 DB_UPDATE_URL={{ db_update_url }}
 DB_UPDATE_INTERVAL_HOURS=24
 SITE_DOMAIN={{ site_domain }}
+{% if ipv4_domain %}
+IPV4_DOMAIN={{ ipv4_domain }}
+{% endif %}
diff --git a/deploy/ansible/roles/app/templates/haproxy.cfg.j2 b/deploy/ansible/roles/app/templates/haproxy.cfg.j2
index b145774..e71f163 100644
--- a/deploy/ansible/roles/app/templates/haproxy.cfg.j2
+++ b/deploy/ansible/roles/app/templates/haproxy.cfg.j2
@@ -36,11 +36,25 @@ frontend http_in
     # Access to port 80 is restricted to Cloudflare IPs at the firewall level
     # All requests reaching HAProxy come from Cloudflare; no additional ACL validation is required.
 
-    # HAProxy's own forwardfor is not enabled; real IP is set explicitly below via CF-Connecting-IP
+{% if ipv4_domain %}
+    # Identify IPv4-only domain traffic by Host header
+    acl is_ipv4_domain hdr(host) -f /usr/local/etc/haproxy/ipv4_domain.lst
 
+{% endif %}
+    # HAProxy's own forwardfor is not enabled; real IP is set explicitly below via CF-Connecting-IP
+{% if ipv4_domain %}
+    # Main domain: standard headers
+    http-request set-header X-Forwarded-For %[req.hdr(CF-Connecting-IP)] if !is_ipv4_domain
+    http-request set-header X-Real-IP      %[req.hdr(CF-Connecting-IP)] if !is_ipv4_domain
+    # IPv4-only domain: separate header to prevent confusion with the main domain
+    http-request set-header X-IPv4-Client-IP %[req.hdr(CF-Connecting-IP)] if is_ipv4_domain
+    http-request del-header X-Forwarded-For if is_ipv4_domain
+    http-request del-header X-Real-IP       if is_ipv4_domain
+{% else %}
     # Overwrite standard headers directly with the real IP forcibly added by Cloudflare
     http-request set-header X-Forwarded-For %[req.hdr(CF-Connecting-IP)]
     http-request set-header X-Real-IP      %[req.hdr(CF-Connecting-IP)]
+{% endif %}
 
     # Rate limiting: tiered based on global request rate
     # Track per-IP request rate (per minute)
@@ -63,7 +77,11 @@ frontend http_in
     default_backend app
 
 frontend https_in
+{% if ipv4_domain %}
+    bind *:443 ssl crt /etc/haproxy/certs/origin.pem crt /etc/haproxy/certs-ipv4/origin.pem alpn h2,http/1.1 strict-sni
+{% else %}
     bind *:443 ssl crt /etc/haproxy/certs/origin.pem alpn h2,http/1.1 strict-sni
+{% endif %}
 
     # Gzip compression
     compression algo gzip
@@ -72,11 +90,25 @@ frontend https_in
     # Access to port 443 is restricted to Cloudflare IPs at the firewall level
     # All requests reaching HAProxy come from Cloudflare; no additional ACL validation is required.
 
-    # HAProxy's own forwardfor is not enabled; real IP is set explicitly below via CF-Connecting-IP
+{% if ipv4_domain %}
+    # Identify IPv4-only domain traffic by Host header
+    acl is_ipv4_domain hdr(host) -f /usr/local/etc/haproxy/ipv4_domain.lst
 
+{% endif %}
+    # HAProxy's own forwardfor is not enabled; real IP is set explicitly below via CF-Connecting-IP
+{% if ipv4_domain %}
+    # Main domain: standard headers
+    http-request set-header X-Forwarded-For %[req.hdr(CF-Connecting-IP)] if !is_ipv4_domain
+    http-request set-header X-Real-IP      %[req.hdr(CF-Connecting-IP)] if !is_ipv4_domain
+    # IPv4-only domain: separate header to prevent confusion with the main domain
+    http-request set-header X-IPv4-Client-IP %[req.hdr(CF-Connecting-IP)] if is_ipv4_domain
+    http-request del-header X-Forwarded-For if is_ipv4_domain
+    http-request del-header X-Real-IP       if is_ipv4_domain
+{% else %}
     # Overwrite standard headers directly with the real IP forcibly added by Cloudflare
     http-request set-header X-Forwarded-For %[req.hdr(CF-Connecting-IP)]
     http-request set-header X-Real-IP      %[req.hdr(CF-Connecting-IP)]
+{% endif %}
 
     # Rate limiting uses the shared stick-table from http_in frontend
     http-request track-sc0 req.hdr(CF-Connecting-IP) table http_in