diff --git a/src/applications/search/engineextension/PhabricatorFerretFulltextEngineExtension.php b/src/applications/search/engineextension/PhabricatorFerretFulltextEngineExtension.php
index bd67f3132c..04d2fad608 100644
--- a/src/applications/search/engineextension/PhabricatorFerretFulltextEngineExtension.php
+++ b/src/applications/search/engineextension/PhabricatorFerretFulltextEngineExtension.php
@@ -1,126 +1,133 @@
 <?php
 
 final class PhabricatorFerretFulltextEngineExtension
   extends PhabricatorFulltextEngineExtension {
 
   const EXTENSIONKEY = 'ferret';
 
 
   public function getExtensionName() {
     return pht('Ferret Fulltext Engine');
   }
 
 
   public function shouldIndexFulltextObject($object) {
     return ($object instanceof PhabricatorFerretInterface);
   }
 
 
   public function indexFulltextObject(
     $object,
     PhabricatorSearchAbstractDocument $document) {
 
     $phid = $document->getPHID();
     $engine = $object->newFerretEngine();
 
     $ferret_document = $engine->newDocumentObject()
       ->setObjectPHID($phid)
       ->setIsClosed(0)
       ->setEpochCreated(0)
       ->setEpochModified(0);
 
     $stemmer = new PhutilSearchStemmer();
 
     $ferret_fields = array();
     $ngrams_source = array();
     foreach ($document->getFieldData() as $field) {
       list($key, $raw_corpus) = $field;
 
       if (!strlen($raw_corpus)) {
         continue;
       }
 
       $normal_corpus = $stemmer->stemCorpus($raw_corpus);
 
       $ferret_fields[] = $engine->newFieldObject()
         ->setFieldKey($key)
         ->setRawCorpus($raw_corpus)
         ->setNormalCorpus($normal_corpus);
 
       $ngrams_source[] = $raw_corpus;
     }
     $ngrams_source = implode(' ', $ngrams_source);
 
     $ngrams = id(new PhabricatorNgramEngine())
       ->getNgramsFromString($ngrams_source, 'index');
 
     $ferret_document->openTransaction();
+
+    try {
       $this->deleteOldDocument($engine, $object, $document);
 
       $ferret_document->save();
 
       $document_id = $ferret_document->getID();
       foreach ($ferret_fields as $ferret_field) {
         $ferret_field
           ->setDocumentID($document_id)
           ->save();
       }
 
       $ferret_ngrams = $engine->newNgramsObject();
       $conn = $ferret_ngrams->establishConnection('w');
 
       $sql = array();
       foreach ($ngrams as $ngram) {
         $sql[] = qsprintf(
           $conn,
           '(%d, %s)',
           $document_id,
           $ngram);
       }
 
       foreach (PhabricatorLiskDAO::chunkSQL($sql) as $chunk) {
         queryfx(
           $conn,
           'INSERT INTO %T (documentID, ngram) VALUES %Q',
           $ferret_ngrams->getTableName(),
           $chunk);
       }
+    } catch (Exception $ex) {
+      $ferret_document->killTransaction();
+      throw $ex;
+    }
+
     $ferret_document->saveTransaction();
   }
 
 
   private function deleteOldDocument(
     PhabricatorFerretEngine $engine,
     $object,
     PhabricatorSearchAbstractDocument $document) {
 
     $old_document = $engine->newDocumentObject()->loadOneWhere(
       'objectPHID = %s',
       $document->getPHID());
     if (!$old_document) {
       return;
     }
 
     $conn = $old_document->establishConnection('w');
     $old_id = $old_document->getID();
 
     queryfx(
       $conn,
       'DELETE FROM %T WHERE id = %d',
       $engine->newDocumentObject()->getTableName(),
       $old_id);
 
     queryfx(
       $conn,
       'DELETE FROM %T WHERE documentID = %d',
       $engine->newFieldObject()->getTableName(),
       $old_id);
 
     queryfx(
       $conn,
       'DELETE FROM %T WHERE documentID = %d',
       $engine->newNgramsObject()->getTableName(),
       $old_id);
   }
 
 }
diff --git a/src/applications/search/ngrams/PhabricatorNgramEngine.php b/src/applications/search/ngrams/PhabricatorNgramEngine.php
index e168a86127..87abdfc446 100644
--- a/src/applications/search/ngrams/PhabricatorNgramEngine.php
+++ b/src/applications/search/ngrams/PhabricatorNgramEngine.php
@@ -1,41 +1,43 @@
 <?php
 
 final class PhabricatorNgramEngine extends Phobject {
 
   public function tokenizeString($value) {
     $value = trim($value, ' ');
     $value = preg_split('/ +/', $value);
     return $value;
   }
 
   public function getNgramsFromString($value, $mode) {
     $tokens = $this->tokenizeString($value);
 
     $ngrams = array();
     foreach ($tokens as $token) {
       $token = phutil_utf8_strtolower($token);
 
       switch ($mode) {
         case 'query':
           break;
         case 'index':
           $token = ' '.$token.' ';
           break;
         case 'prefix':
           $token = ' '.$token;
           break;
       }
 
-      $len = (strlen($token) - 2);
+      $token_v = phutil_utf8v($token);
+      $len = (count($token_v) - 2);
       for ($ii = 0; $ii < $len; $ii++) {
-        $ngram = substr($token, $ii, 3);
+        $ngram = array_slice($token_v, $ii, 3);
+        $ngram = implode('', $ngram);
         $ngrams[$ngram] = $ngram;
       }
     }
 
     ksort($ngrams);
 
     return array_keys($ngrams);
   }
 
 }