diff --git a/database.go b/database.go
index d488ccb78b358e3c9bac00d2e38c46d9125b9a18..101e413daad0e11efb6f242afe1b21db1ac9af93 100644
--- a/database.go
+++ b/database.go
@@ -152,7 +152,7 @@ func defaultIndexMapping() *bleve.IndexMapping {
 		map[string]interface{}{
 			"type":      "custom",
 			"tokenizer": "unicode",
-			"token_filters": []string{
+			"token_filters": []interface{}{
 				"to_lower",
 				"stop_en",
 				"edgeNgram325",