diff --git a/src/applications/project/customfield/PhabricatorProjectCustomField.php b/src/applications/project/customfield/PhabricatorProjectCustomField.php
--- a/src/applications/project/customfield/PhabricatorProjectCustomField.php
+++ b/src/applications/project/customfield/PhabricatorProjectCustomField.php
@@ -3,5 +3,16 @@
 abstract class PhabricatorProjectCustomField
   extends PhabricatorCustomField {
 
+  public function newStorageObject() {
+    return new PhabricatorProjectCustomFieldStorage();
+  }
+
+  protected function newStringIndexStorage() {
+    return new PhabricatorProjectCustomFieldStringIndex();
+  }
+
+  protected function newNumericIndexStorage() {
+    return new PhabricatorProjectCustomFieldNumericIndex();
+  }
 
 }