diff --git a/src/__phutil_library_map__.php b/src/__phutil_library_map__.php
index c0873d286d..5bf6aceb21 100644
--- a/src/__phutil_library_map__.php
+++ b/src/__phutil_library_map__.php
@@ -696,6 +696,7 @@ phutil_register_library_map(array(
     'PhabricatorFeedStoryCommit' => 'applications/feed/story/PhabricatorFeedStoryCommit.php',
     'PhabricatorFeedStoryData' => 'applications/feed/storage/PhabricatorFeedStoryData.php',
     'PhabricatorFeedStoryDifferential' => 'applications/feed/story/PhabricatorFeedStoryDifferential.php',
+    'PhabricatorFeedStoryDifferentialAggregate' => 'applications/feed/story/PhabricatorFeedStoryDifferentialAggregate.php',
     'PhabricatorFeedStoryManiphest' => 'applications/feed/story/PhabricatorFeedStoryManiphest.php',
     'PhabricatorFeedStoryManiphestAggregate' => 'applications/feed/story/PhabricatorFeedStoryManiphestAggregate.php',
     'PhabricatorFeedStoryNotification' => 'applications/notification/storage/PhabricatorFeedStoryNotification.php',
@@ -1820,6 +1821,7 @@ phutil_register_library_map(array(
     'PhabricatorFeedStoryCommit' => 'PhabricatorFeedStory',
     'PhabricatorFeedStoryData' => 'PhabricatorFeedDAO',
     'PhabricatorFeedStoryDifferential' => 'PhabricatorFeedStory',
+    'PhabricatorFeedStoryDifferentialAggregate' => 'PhabricatorFeedStoryAggregate',
     'PhabricatorFeedStoryManiphest' => 'PhabricatorFeedStory',
     'PhabricatorFeedStoryManiphestAggregate' => 'PhabricatorFeedStoryAggregate',
     'PhabricatorFeedStoryNotification' => 'PhabricatorFeedDAO',
diff --git a/src/applications/feed/story/PhabricatorFeedStoryDifferential.php b/src/applications/feed/story/PhabricatorFeedStoryDifferential.php
index 25174bf242..cde2122d93 100644
--- a/src/applications/feed/story/PhabricatorFeedStoryDifferential.php
+++ b/src/applications/feed/story/PhabricatorFeedStoryDifferential.php
@@ -92,4 +92,18 @@ final class PhabricatorFeedStoryDifferential extends PhabricatorFeedStory {
 
     return $one_line;
   }
+
+  public function getNotificationAggregations() {
+    $class = get_class($this);
+    $phid  = $this->getStoryData()->getValue('revision_phid');
+    $read  = (int)$this->getHasViewed();
+
+    // Don't aggregate updates separated by more than 2 hours.
+    $block = (int)($this->getEpoch() / (60 * 60 * 2));
+
+    return array(
+      "{$class}:{$phid}:{$read}:{$block}"
+        => 'PhabricatorFeedStoryDifferentialAggregate',
+    );
+  }
 }
diff --git a/src/applications/feed/story/PhabricatorFeedStoryDifferentialAggregate.php b/src/applications/feed/story/PhabricatorFeedStoryDifferentialAggregate.php
new file mode 100644
index 0000000000..51ade007b5
--- /dev/null
+++ b/src/applications/feed/story/PhabricatorFeedStoryDifferentialAggregate.php
@@ -0,0 +1,86 @@
+<?php
+
+/*
+ * Copyright 2012 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.
+ */
+
+final class PhabricatorFeedStoryDifferentialAggregate
+  extends PhabricatorFeedStoryAggregate {
+
+  public function renderView() {
+    return null;
+  }
+
+
+  public function renderNotificationView() {
+    $data = $this->getStoryData();
+
+    $task_link = $this->linkTo($data->getValue('revision_phid'));
+
+    $authors = $this->getAuthorPHIDs();
+
+    // TODO: These aren't really translatable because linkTo() returns a
+    // string, not an object with a gender.
+
+    switch (count($authors)) {
+      case 1:
+        $author = $this->linkTo(array_shift($authors));
+        $title = pht(
+          '%s made multiple updates to %s',
+          $author,
+          $task_link);
+        break;
+      case 2:
+        $author1 = $this->linkTo(array_shift($authors));
+        $author2 = $this->linkTo(array_shift($authors));
+        $title = pht(
+          '%s and %s made multiple updates to %s',
+          $author1,
+          $author2,
+          $task_link);
+        break;
+      case 3:
+        $author1 = $this->linkTo(array_shift($authors));
+        $author2 = $this->linkTo(array_shift($authors));
+        $author3 = $this->linkTo(array_shift($authors));
+        $title = pht(
+          '%s, %s, and %s made multiple updates to %s',
+          $author1,
+          $author2,
+          $author3,
+          $task_link);
+        break;
+      default:
+        $author1 = $this->linkTo(array_shift($authors));
+        $author2 = $this->linkTo(array_shift($authors));
+        $others  = count($authors);
+        $title = pht(
+          '%s, %s, and %d others made multiple updates to %s',
+          $author1,
+          $author2,
+          $others,
+          $task_link);
+        break;
+    }
+
+    $view = new PhabricatorNotificationStoryView();
+    $view->setEpoch($this->getEpoch());
+    $view->setViewed($this->getHasViewed());
+    $view->setTitle($title);
+
+    return $view;
+  }
+
+}