diff --git a/src/applications/search/engine/PhabricatorSearchEngineElastic.php b/src/applications/search/engine/PhabricatorSearchEngineElastic.php
--- a/src/applications/search/engine/PhabricatorSearchEngineElastic.php
+++ b/src/applications/search/engine/PhabricatorSearchEngineElastic.php
@@ -275,8 +275,12 @@
     $types = array_keys(
       PhabricatorSearchApplicationSearchEngine::getIndexableDocumentTypes());
     foreach ($types as $type) {
+      // Use the custom trigram analyzer for the corpus of text
       $data['mappings'][$type]['properties']['field']['properties']['corpus'] =
         array( 'type' => 'string', 'analyzer' => 'custom_trigrams' );
+
+      // Ensure we have dateCreated since the default query requires it
+      $data['mappings'][$type]['properties']['dateCreated']['type'] = 'string';
     }
 
     return $data;