diff --git a/custom-domain/dstack-ingress/DNS_PROVIDERS.md b/custom-domain/dstack-ingress/DNS_PROVIDERS.md
index 845d288..40c0ffb 100644
--- a/custom-domain/dstack-ingress/DNS_PROVIDERS.md
+++ b/custom-domain/dstack-ingress/DNS_PROVIDERS.md
@@ -24,6 +24,7 @@ This guide explains how to configure dstack-ingress to work with different DNS p
 - `SET_CAA` - Enable CAA record setup (default: false)
 - `PORT` - HTTPS port (default: 443)
 - `TXT_PREFIX` - Prefix for TXT records (default: "_tapp-address")
+- `ALIAS_DOMAIN` - An additional domain to include as a Subject Alternative Name (SAN) on the TLS certificate and in nginx `server_name`. When set, the node's certificate covers both `DOMAIN` and `ALIAS_DOMAIN`, and nginx will accept requests for either hostname.
 
 ## Provider-Specific Configuration
 
diff --git a/custom-domain/dstack-ingress/README.md b/custom-domain/dstack-ingress/README.md
index d166cd2..925f8e6 100644
--- a/custom-domain/dstack-ingress/README.md
+++ b/custom-domain/dstack-ingress/README.md
@@ -217,6 +217,7 @@ configs:
 - `PROXY_BUFFERS`: Optional value for nginx `proxy_buffers` (format: `number size`, e.g. `4 256k`) in single-domain mode
 - `PROXY_BUSY_BUFFERS_SIZE`: Optional value for nginx `proxy_busy_buffers_size` (numeric with optional `k|m` suffix, e.g. `256k`) in single-domain mode
 - `CERTBOT_STAGING`: Optional; set this value to the string `true` to set the `--staging` server option on the [`certbot` cli](https://eff-certbot.readthedocs.io/en/stable/using.html#certbot-command-line-options)
+- `ALIAS_DOMAIN`: An additional domain to include as a Subject Alternative Name (SAN) on the TLS certificate and in nginx `server_name`. When set, the node's certificate covers both `DOMAIN` and `ALIAS_DOMAIN`, and nginx will accept requests for either hostname.
 
 **Backward Compatibility:**
 
diff --git a/custom-domain/dstack-ingress/scripts/certman.py b/custom-domain/dstack-ingress/scripts/certman.py
index 52126d2..5c81a16 100644
--- a/custom-domain/dstack-ingress/scripts/certman.py
+++ b/custom-domain/dstack-ingress/scripts/certman.py
@@ -288,6 +288,9 @@ def _build_certbot_command(self, action: str, domain: str, email: str) -> List[s
         if action == "certonly":
             base_cmd.extend(["--agree-tos", "--no-eff-email",
                             "--email", email, "-d", domain])
+            alias_domain = os.environ.get("ALIAS_DOMAIN", "").strip()
+            if alias_domain:
+                base_cmd.extend(["--cert-name", domain, "--expand", "-d", alias_domain])
         if os.environ.get("CERTBOT_STAGING", "false") == "true":
             base_cmd.extend(["--staging"])
 
diff --git a/custom-domain/dstack-ingress/scripts/entrypoint.sh b/custom-domain/dstack-ingress/scripts/entrypoint.sh
index d1994a3..5777f6e 100644
--- a/custom-domain/dstack-ingress/scripts/entrypoint.sh
+++ b/custom-domain/dstack-ingress/scripts/entrypoint.sh
@@ -40,6 +40,9 @@ fi
 if ! TXT_PREFIX=$(sanitize_dns_label "$TXT_PREFIX"); then
     exit 1
 fi
+if ! ALIAS_DOMAIN=$(sanitize_domain "$ALIAS_DOMAIN"); then
+    exit 1
+fi
 
 PROXY_CMD="proxy"
 if [[ "${TARGET_ENDPOINT}" == grpc://* ]]; then
@@ -144,11 +147,16 @@ setup_nginx_conf() {
         proxy_busy_buffers_size_conf="    proxy_busy_buffers_size ${PROXY_BUSY_BUFFERS_SIZE};"
     fi
 
+    local server_name_value="${DOMAIN}"
+    if [ -n "$ALIAS_DOMAIN" ]; then
+        server_name_value="${DOMAIN} ${ALIAS_DOMAIN}"
+    fi
+
     cat <<EOF >/etc/nginx/conf.d/default.conf
 server {
     listen ${PORT} ssl;
     http2 on;
-    server_name ${DOMAIN};
+    server_name ${server_name_value};
 
     # SSL certificate configuration
     ssl_certificate /etc/letsencrypt/live/${cert_name}/fullchain.pem;