diff --git a/core/src/main/javascript/google/registry/ui/js/registrar/registry_lock.js b/core/src/main/javascript/google/registry/ui/js/registrar/registry_lock.js
index 27e71731f..a36f3fbbb 100644
--- a/core/src/main/javascript/google/registry/ui/js/registrar/registry_lock.js
+++ b/core/src/main/javascript/google/registry/ui/js/registrar/registry_lock.js
@@ -167,6 +167,7 @@ registry.registrar.RegistryLock.prototype.lockOrUnlockDomain_ = function(isLock,
   var domain = goog.dom.getRequiredElement('domain-lock-input-value').value;
   var passwordElem = goog.dom.getElement('domain-lock-password');
   var password = passwordElem == null ? null : passwordElem.value;
+  var relockDuration = this.getRelockDurationFromModal_()
   goog.net.XhrIo.send('/registry-lock-post',
       e => this.fillLocksPage_(e),
       'POST',
@@ -174,13 +175,30 @@ registry.registrar.RegistryLock.prototype.lockOrUnlockDomain_ = function(isLock,
         'clientId': this.clientId,
         'fullyQualifiedDomainName': domain,
         'isLock': isLock,
-        'password': password
+        'password': password,
+        'relockDurationMillis': relockDuration
       }), {
         'X-CSRF-Token': this.xsrfToken,
         'Content-Type': 'application/json; charset=UTF-8'
       });
 }
 
+/**
+ * Returns the duration after which we will re-lock a locked domain. Will return null if we
+ * are locking a domain, or if the user selects the "Never" option
+ * @private
+ */
+registry.registrar.RegistryLock.prototype.getRelockDurationFromModal_ = function() {
+  var inputElements = goog.dom.getElementsByTagNameAndClass("input", "relock-duration-input");
+  for (var i = 0; i < inputElements.length; i++) {
+    var elem = inputElements[i];
+    if (elem.checked && elem.value !== "0") {
+      return elem.value;
+    }
+  }
+  return null;
+}
+
 /**
  * Click handler for unlocking domains (button click).
  * @private
diff --git a/core/src/main/resources/google/registry/ui/soy/registrar/RegistryLock.soy b/core/src/main/resources/google/registry/ui/soy/registrar/RegistryLock.soy
index c81c9245e..bce2ac5c0 100644
--- a/core/src/main/resources/google/registry/ui/soy/registrar/RegistryLock.soy
+++ b/core/src/main/resources/google/registry/ui/soy/registrar/RegistryLock.soy
@@ -132,6 +132,24 @@
         <input type="password" id="domain-lock-password">
         <br>
       {/if}
+      {if not $isLock}
+        <div>
+          <br>
+          <p>Automatically re-lock the domain after:</p>
+          <input type="radio" name="relock-duration" id="one-hour-duration" value="3600000"
+                 class="relock-duration-input">
+          <label for="one-hour-duration">1 hour</label><br>
+          <input type="radio" name="relock-duration" id="six-hour-duration" value="21600000"
+                 class="relock-duration-input" checked>
+          <label for="six-hour-duration">6 hours</label><br>
+          <input type="radio" name="relock-duration" id="twenty-four-hour-duration" value="86400000"
+                 class="relock-duration-input">
+          <label for="twenty-four-hour-duration">24 hours</label><br>
+          <input type="radio" name="relock-duration" id="never-relock-duration" value="0"
+                 class="relock-duration-input">
+          <label for="never-relock-duration">Never</label><br>
+        </div>
+      {/if}
       <div id="modal-error-message" hidden class="{css('kd-errormessage')}"></div>
       <div class="{css('buttons-div')}">
         <button id="domain-lock-cancel" class="{css('kd-button')}">Cancel</button>
diff --git a/core/src/test/resources/google/registry/webdriver/goldens/chrome-linux/RegistrarConsoleScreenshotTest_registryLock_unlockModal_page.png b/core/src/test/resources/google/registry/webdriver/goldens/chrome-linux/RegistrarConsoleScreenshotTest_registryLock_unlockModal_page.png
index d2bd491e5..187c140b2 100644
Binary files a/core/src/test/resources/google/registry/webdriver/goldens/chrome-linux/RegistrarConsoleScreenshotTest_registryLock_unlockModal_page.png and b/core/src/test/resources/google/registry/webdriver/goldens/chrome-linux/RegistrarConsoleScreenshotTest_registryLock_unlockModal_page.png differ