diff --git a/src/__phutil_library_map__.php b/src/__phutil_library_map__.php
--- a/src/__phutil_library_map__.php
+++ b/src/__phutil_library_map__.php
@@ -544,6 +544,7 @@
     'DifferentialRevisionHeraldField' => 'applications/differential/herald/DifferentialRevisionHeraldField.php',
     'DifferentialRevisionHeraldFieldGroup' => 'applications/differential/herald/DifferentialRevisionHeraldFieldGroup.php',
     'DifferentialRevisionIDCommitMessageField' => 'applications/differential/field/DifferentialRevisionIDCommitMessageField.php',
+    'DifferentialRevisionInlineTransaction' => 'applications/differential/xaction/DifferentialRevisionInlineTransaction.php',
     'DifferentialRevisionInlinesController' => 'applications/differential/controller/DifferentialRevisionInlinesController.php',
     'DifferentialRevisionListController' => 'applications/differential/controller/DifferentialRevisionListController.php',
     'DifferentialRevisionListView' => 'applications/differential/view/DifferentialRevisionListView.php',
@@ -5547,6 +5548,7 @@
     'DifferentialRevisionHeraldField' => 'HeraldField',
     'DifferentialRevisionHeraldFieldGroup' => 'HeraldFieldGroup',
     'DifferentialRevisionIDCommitMessageField' => 'DifferentialCommitMessageField',
+    'DifferentialRevisionInlineTransaction' => 'PhabricatorModularTransactionType',
     'DifferentialRevisionInlinesController' => 'DifferentialController',
     'DifferentialRevisionListController' => 'DifferentialController',
     'DifferentialRevisionListView' => 'AphrontView',
diff --git a/src/applications/differential/xaction/DifferentialRevisionInlineTransaction.php b/src/applications/differential/xaction/DifferentialRevisionInlineTransaction.php
new file mode 100644
--- /dev/null
+++ b/src/applications/differential/xaction/DifferentialRevisionInlineTransaction.php
@@ -0,0 +1,53 @@
+<?php
+
+final class DifferentialRevisionInlineTransaction
+  extends PhabricatorModularTransactionType {
+
+  // NOTE: This class is NOT an actual Differential modular transaction type!
+  // It does not extend "DifferentialRevisionTransactionType". Some day it
+  // should, but for now it's just reducing the amount of hackiness around
+  // supporting inline comments in the "transaction.search" Conduit API method.
+
+  const TRANSACTIONTYPE = 'internal.pretend-inline';
+
+  public function getTransactionTypeForConduit($xaction) {
+    return 'inline';
+  }
+
+  public function loadTransactionTypeConduitData(array $xactions) {
+    $viewer = $this->getViewer();
+
+    $changeset_ids = array();
+    foreach ($xactions as $xaction) {
+      $changeset_ids[] = $xaction->getComment()->getChangesetID();
+    }
+
+    $changesets = id(new DifferentialChangesetQuery())
+      ->setViewer($viewer)
+      ->withIDs($changeset_ids)
+      ->execute();
+
+    $changesets = mpull($changesets, null, 'getID');
+
+    return $changesets;
+  }
+
+  public function getFieldValuesForConduit($object, $data) {
+    $comment = $object->getComment();
+
+    $changeset = $data[$comment->getChangesetID()];
+    $diff = $changeset->getDiff();
+
+    return array(
+      'diff' => array(
+        'id' => $diff->getID(),
+        'phid' => $diff->getPHID(),
+      ),
+      'path' => $changeset->getDisplayFilename(),
+      'line' => (int)$comment->getLineNumber(),
+      'length' => (int)($comment->getLineLength() + 1),
+      'replyToCommentPHID' => $comment->getReplyToCommentPHID(),
+    );
+  }
+
+}
diff --git a/src/applications/transactions/conduit/TransactionSearchConduitAPIMethod.php b/src/applications/transactions/conduit/TransactionSearchConduitAPIMethod.php
--- a/src/applications/transactions/conduit/TransactionSearchConduitAPIMethod.php
+++ b/src/applications/transactions/conduit/TransactionSearchConduitAPIMethod.php
@@ -97,7 +97,18 @@
         continue;
       }
 
-      $modular_template = $xaction->getModularType();
+      // TODO: Hack things so certain transactions which don't have a modular
+      // type yet can use a pseudotype until they modularize. Some day, we'll
+      // modularize everything and remove this.
+      switch ($xaction->getTransactionType()) {
+        case DifferentialTransaction::TYPE_INLINE:
+          $modular_template = new DifferentialRevisionInlineTransaction();
+          break;
+        default:
+          $modular_template = $xaction->getModularType();
+          break;
+      }
+
       $modular_class = get_class($modular_template);
       if (!isset($modular_objects[$modular_class])) {
         try {
@@ -173,6 +184,16 @@
         $fields = (object)$fields;
       }
 
+      // If we haven't found a modular type, fallback for some simple core
+      // types. Ideally, we'll modularize everything some day.
+      if ($type === null) {
+        switch ($xaction->getTransactionType()) {
+          case PhabricatorTransactions::TYPE_COMMENT:
+            $type = 'comment';
+            break;
+        }
+      }
+
       $data[] = array(
         'id' => (int)$xaction->getID(),
         'phid' => (string)$xaction->getPHID(),