diff --git a/code/MSSQLDatabase.php b/code/MSSQLDatabase.php
index 8924194..ef17e44 100644
--- a/code/MSSQLDatabase.php
+++ b/code/MSSQLDatabase.php
@@ -1303,7 +1303,7 @@ class MSSQLDatabase extends SS_Database {
 
 		$allClassesToSearch = array();
 		foreach ($classesToSearch as $class) {
-			$allClassesToSearch = array_merge($allClassesToSearch, ClassInfo::dataClassesFor($class));
+			$allClassesToSearch = array_merge($allClassesToSearch, ClassInfo::getValidSubClasses($class));
 		}
 		$allClassesToSearch = array_unique($allClassesToSearch);