diff --git a/README.md b/README.md
index e2d03fa..acc4513 100644
--- a/README.md
+++ b/README.md
@@ -56,7 +56,9 @@ The following environment variables can be used to customize the Certbot contain
 
 | Variable               | Description                                                         | Default Value |
 |------------------------|---------------------------------------------------------------------|---------------|
-| `CERTBOT_DOMAINS`      | Comma-separated list of domains for which to obtain the certificate | - |
+| `CERTBOT_DOMAINS`      | Comma-separated list of domains for which to obtain the certificate (example: `example.com,www.example.com`) | - |
+| `CERTBOT_CERT_NAME`    | Explicit certificate name to update/modify ([See official docs →](https://eff-certbot.readthedocs.io/en/stable/using.html#changing-a-certificate-s-domains)) | - |
+| `CERTBOT_EXPAND`       | **DEPRECATED**: Expand existing certificate to add domains (use CERTBOT_CERT_NAME instead, [see official docs →](https://eff-certbot.readthedocs.io/en/stable/using.html#re-creating-and-updating-existing-certificates)) | `false` |
 | `CERTBOT_EMAIL`        | Email address for Let's Encrypt notifications                       | - |
 | `CERTBOT_KEY_TYPE`     | Type of private key to generate                                     | `ecdsa` |
 | `CERTBOT_SERVER`       | The ACME server URL                                                 | `https://acme-v02.api.letsencrypt.org/directory` |
diff --git a/src/Dockerfile b/src/Dockerfile
index eec6266..2a2479e 100644
--- a/src/Dockerfile
+++ b/src/Dockerfile
@@ -9,6 +9,8 @@ ARG CERTBOT_GID=9999
 
 ENV CERTBOT_DOMAINS="" \
     CERTBOT_EMAIL="" \
+    CERTBOT_EXPAND=false \
+    CERTBOT_CERT_NAME="" \
     CERTBOT_KEY_TYPE="ecdsa" \
     CERTBOT_SERVER="https://acme-v02.api.letsencrypt.org/directory" \
     CLOUDFLARE_API_TOKEN="" \
diff --git a/src/entrypoint.sh b/src/entrypoint.sh
index e3b2a35..6f77ee9 100644
--- a/src/entrypoint.sh
+++ b/src/entrypoint.sh
@@ -105,6 +105,16 @@ run_certbot() {
     debug_flag=""
     [ "$DEBUG" = "true" ] && debug_flag="-v"
 
+     # Build additional certbot flags using positional parameters
+    set --  # Reset positional parameters
+    
+    if [ -n "$CERTBOT_CERT_NAME" ]; then
+        set -- "$@" --cert-name "$CERTBOT_CERT_NAME"
+    elif [ "$CERTBOT_EXPAND" = "true" ]; then
+        set -- "$@" --expand
+    fi
+
+    # Run certbot command
     $certbot_cmd $debug_flag certonly \
         --dns-cloudflare \
         --dns-cloudflare-credentials "$CLOUDFLARE_CREDENTIALS_FILE" \
@@ -115,7 +125,8 @@ run_certbot() {
         --server "$CERTBOT_SERVER" \
         --agree-tos \
         --non-interactive \
-        --strict-permissions
+        --strict-permissions \
+        "$@"
     exit_code=$?
     if [ $exit_code -ne 0 ]; then
         echo "Error: certbot command failed with exit code $exit_code"