diff --git a/src/__phutil_library_map__.php b/src/__phutil_library_map__.php
index 65187fe2a0..926a6a2d33 100644
--- a/src/__phutil_library_map__.php
+++ b/src/__phutil_library_map__.php
@@ -68,6 +68,7 @@ phutil_register_library_map(array(
     'ConduitAPI_differential_createrevision_Method' => 'applications/conduit/method/differential/createrevision',
     'ConduitAPI_differential_find_Method' => 'applications/conduit/method/differential/find',
     'ConduitAPI_differential_getcommitmessage_Method' => 'applications/conduit/method/differential/getcommitmessage',
+    'ConduitAPI_differential_markcommitted_Method' => 'applications/conduit/method/differential/markcommitted',
     'ConduitAPI_differential_parsecommitmessage_Method' => 'applications/conduit/method/differential/parsecommitmessage',
     'ConduitAPI_differential_setdiffproperty_Method' => 'applications/conduit/method/differential/setdiffproperty',
     'ConduitAPI_differential_updaterevision_Method' => 'applications/conduit/method/differential/updaterevision',
@@ -296,6 +297,7 @@ phutil_register_library_map(array(
     'ConduitAPI_differential_createrevision_Method' => 'ConduitAPIMethod',
     'ConduitAPI_differential_find_Method' => 'ConduitAPIMethod',
     'ConduitAPI_differential_getcommitmessage_Method' => 'ConduitAPIMethod',
+    'ConduitAPI_differential_markcommitted_Method' => 'ConduitAPIMethod',
     'ConduitAPI_differential_parsecommitmessage_Method' => 'ConduitAPIMethod',
     'ConduitAPI_differential_setdiffproperty_Method' => 'ConduitAPIMethod',
     'ConduitAPI_differential_updaterevision_Method' => 'ConduitAPIMethod',
diff --git a/src/applications/conduit/method/differential/markcommitted/ConduitAPI_differential_markcommitted_Method.php b/src/applications/conduit/method/differential/markcommitted/ConduitAPI_differential_markcommitted_Method.php
new file mode 100644
index 0000000000..ec8858c28a
--- /dev/null
+++ b/src/applications/conduit/method/differential/markcommitted/ConduitAPI_differential_markcommitted_Method.php
@@ -0,0 +1,74 @@
+<?php
+
+/*
+ * Copyright 2011 Facebook, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+class ConduitAPI_differential_markcommitted_Method extends ConduitAPIMethod {
+
+  public function getMethodDescription() {
+    return "Mark Differential revisions as committed.";
+  }
+
+  public function defineParamTypes() {
+    return array(
+      'revision_id' => 'required revision_id',
+    );
+  }
+
+  public function defineReturnType() {
+    return 'void';
+  }
+
+  public function defineErrorTypes() {
+    return array(
+      'ERR_NOT_FOUND' => 'Revision was not found.',
+    );
+  }
+
+  protected function execute(ConduitAPIRequest $request) {
+    $id = $request->getValue('revision_id');
+
+    $revision = id(new DifferentialRevision())->load($id);
+    if (!$revision) {
+      throw new ConduitException('ERR_NOT_FOUND');
+    }
+
+    if ($revision->getStatus() == DifferentialRevisionStatus::COMMITTED) {
+      // This can occur if someone runs 'mark-committed' and hits a race, or
+      // they have a remote hook installed but don't have the
+      // 'remote_hook_installed' flag set, or similar. In any case, just treat
+      // it as a no-op rather than adding another "X committed this revision"
+      // message to the revision comments.
+      return;
+    }
+
+    $revision->loadRelationships();
+
+    $editor = new DifferentialCommentEditor(
+      $revision,
+      $revision->getAuthorPHID(),
+      DifferentialAction::ACTION_COMMIT,
+      $inline_comments = array());
+    $editor->save();
+
+    $revision->setStatus(DifferentialRevisionStatus::COMMITTED);
+    $revision->setDateCommitted(time());
+    $revision->save();
+
+    return;
+  }
+
+}
diff --git a/src/applications/conduit/method/differential/markcommitted/__init__.php b/src/applications/conduit/method/differential/markcommitted/__init__.php
new file mode 100644
index 0000000000..7dcc2ff73b
--- /dev/null
+++ b/src/applications/conduit/method/differential/markcommitted/__init__.php
@@ -0,0 +1,19 @@
+<?php
+/**
+ * This file is automatically generated. Lint this module to rebuild it.
+ * @generated
+ */
+
+
+
+phutil_require_module('phabricator', 'applications/conduit/method/base');
+phutil_require_module('phabricator', 'applications/conduit/protocol/exception');
+phutil_require_module('phabricator', 'applications/differential/constants/action');
+phutil_require_module('phabricator', 'applications/differential/constants/revisionstatus');
+phutil_require_module('phabricator', 'applications/differential/editor/comment');
+phutil_require_module('phabricator', 'applications/differential/storage/revision');
+
+phutil_require_module('phutil', 'utils');
+
+
+phutil_require_source('ConduitAPI_differential_markcommitted_Method.php');