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
@@ -4313,7 +4313,6 @@
     'PhabricatorQueryOrderItem' => 'infrastructure/query/order/PhabricatorQueryOrderItem.php',
     'PhabricatorQueryOrderTestCase' => 'infrastructure/query/order/__tests__/PhabricatorQueryOrderTestCase.php',
     'PhabricatorQueryOrderVector' => 'infrastructure/query/order/PhabricatorQueryOrderVector.php',
-    'PhabricatorQuickSearchEngineExtension' => 'applications/search/engineextension/PhabricatorQuickSearchEngineExtension.php',
     'PhabricatorRateLimitRequestExceptionHandler' => 'aphront/handler/PhabricatorRateLimitRequestExceptionHandler.php',
     'PhabricatorRebuildIndexesWorker' => 'applications/search/worker/PhabricatorRebuildIndexesWorker.php',
     'PhabricatorRecaptchaConfigOptions' => 'applications/config/option/PhabricatorRecaptchaConfigOptions.php',
@@ -10552,7 +10551,6 @@
       'Phobject',
       'Iterator',
     ),
-    'PhabricatorQuickSearchEngineExtension' => 'PhabricatorDatasourceEngineExtension',
     'PhabricatorRateLimitRequestExceptionHandler' => 'PhabricatorRequestExceptionHandler',
     'PhabricatorRebuildIndexesWorker' => 'PhabricatorWorker',
     'PhabricatorRecaptchaConfigOptions' => 'PhabricatorApplicationConfigOptions',
diff --git a/src/applications/search/engineextension/PhabricatorQuickSearchEngineExtension.php b/src/applications/search/engineextension/PhabricatorQuickSearchEngineExtension.php
deleted file mode 100644
--- a/src/applications/search/engineextension/PhabricatorQuickSearchEngineExtension.php
+++ /dev/null
@@ -1,6 +0,0 @@
-<?php
-
-// TODO: This is an older name "PhabricatorDatasourceEngineExtension" purely
-// to preserve compatibility that should be removed soon.
-abstract class PhabricatorQuickSearchEngineExtension
-  extends PhabricatorDatasourceEngineExtension {}