diff --git a/src/main/java/com/resend/services/domains/model/Tls.java b/src/main/java/com/resend/services/domains/model/Tls.java
new file mode 100644
index 0000000..6cde4f4
--- /dev/null
+++ b/src/main/java/com/resend/services/domains/model/Tls.java
@@ -0,0 +1,48 @@
+package com.resend.services.domains.model;
+
+/**
+ * Enum representing the TLS settings for a domain.
+ */
+public enum Tls {
+    /**
+     *  Represents an enforced TLS setting.
+     */
+    ENFORCED("enforced"),
+    /**
+     *  Represents an opportunistic TLS setting.
+     */
+    OPPORTUNISTIC("opportunistic");
+
+    /**
+     * Holds the string representation of the enum value.
+     */
+    private final String value;
+
+    /**
+     * Constructor for the Tls enum.
+     *
+     * @param value The string representation of the TLS setting.
+     */
+    Tls(String value) {
+        this.value = value;
+    }
+
+    /**
+     * Retrieves the string representation of the TLS setting.
+     *
+     * @return The string representation of the TLS setting.
+     */
+    public String getValue() {
+        return value;
+    }
+
+    /**
+     * Returns the string representation of the TLS setting.
+     *
+     * @return The string representation of the TLS setting.
+     */
+    @Override
+    public String toString() {
+        return this.value;
+    }
+}
diff --git a/src/main/java/com/resend/services/domains/model/UpdateDomainOptions.java b/src/main/java/com/resend/services/domains/model/UpdateDomainOptions.java
index d603c46..2327ea7 100644
--- a/src/main/java/com/resend/services/domains/model/UpdateDomainOptions.java
+++ b/src/main/java/com/resend/services/domains/model/UpdateDomainOptions.java
@@ -15,6 +15,8 @@ public class UpdateDomainOptions {
     @JsonProperty("open_tracking")
     private final boolean openTracking;
 
+    @JsonProperty("tls")
+    private final Tls tls;
     /**
      * Constructs a UpdateDomainOptions object using the provided builder.
      *
@@ -24,6 +26,7 @@ public UpdateDomainOptions(Builder builder) {
         this.id = builder.id;
         this.clickTracking = builder.clickTracking;
         this.openTracking = builder.openTracking;
+        this.tls = builder.tls;
     }
 
     /**
@@ -53,6 +56,15 @@ public boolean getOpenTracking() {
         return openTracking;
     }
 
+    /**
+     * Get the TLS setting for the domain.
+     *
+     * @return The TLS setting for the domain.
+     */
+    public Tls getTls() {
+        return tls;
+    }
+
     /**
      * Create a new builder instance for constructing UpdateDomainOptions objects.
      *
@@ -69,6 +81,7 @@ public static class Builder {
         private String id;
         private boolean clickTracking;
         private boolean openTracking;
+        private Tls tls;
 
         /**
          * Set the id of the domain.
@@ -103,6 +116,17 @@ public Builder openTracking(boolean openTracking) {
             return this;
         }
 
+        /**
+         * Set the TLS setting for the domain.
+         *
+         * @param tls The TLS setting for the domain.
+         * @return The builder instance.
+         */
+        public Builder tls(Tls tls) {
+            this.tls = tls;
+            return this;
+        }
+
         /**
          * Build a new UpdateDomainOptions object.
          *
diff --git a/src/test/java/com/resend/services/util/DomainsUtil.java b/src/test/java/com/resend/services/util/DomainsUtil.java
index 21e214a..1923c02 100644
--- a/src/test/java/com/resend/services/util/DomainsUtil.java
+++ b/src/test/java/com/resend/services/util/DomainsUtil.java
@@ -59,6 +59,7 @@ public static final UpdateDomainOptions updateDomainRequest() {
         return UpdateDomainOptions.builder()
                 .openTracking(true)
                 .clickTracking(true)
+                .tls(Tls.OPPORTUNISTIC)
                 .id("2c64b27c-6237-4626-85d2-a0a8b5832070")
                 .build();
     }