diff --git a/internal/bootstrap/data/setting.go b/internal/bootstrap/data/setting.go
index 62dabf9e..6235a26a 100644
--- a/internal/bootstrap/data/setting.go
+++ b/internal/bootstrap/data/setting.go
@@ -82,8 +82,9 @@ func initialSettings() {
 		{Key: conf.AudioTypes, Value: "mp3,flac,ogg,m4a,wav,opus", Type: conf.TypeText, Group: model.PREVIEW, Flag: model.PRIVATE},
 		{Key: conf.VideoTypes, Value: "mp4,mkv,avi,mov,rmvb,webm,flv", Type: conf.TypeText, Group: model.PREVIEW, Flag: model.PRIVATE},
 		{Key: conf.ImageTypes, Value: "jpg,tiff,jpeg,png,gif,bmp,svg,ico,swf,webp", Type: conf.TypeText, Group: model.PREVIEW, Flag: model.PRIVATE},
-		{Key: conf.OfficeTypes, Value: "doc,docx,xls,xlsx,ppt,pptx,pdf", Type: conf.TypeText, Group: model.PREVIEW, Flag: model.PRIVATE},
+		{Key: conf.OfficeTypes, Value: "doc,docx,xls,xlsx,ppt,pptx", Type: conf.TypeText, Group: model.PREVIEW, Flag: model.PRIVATE},
 		{Key: conf.ProxyTypes, Value: "m3u8", Type: conf.TypeText, Group: model.PREVIEW, Flag: model.PRIVATE},
+		{Key: "external_previews", Value: `{}`, Type: conf.TypeText, Group: model.PREVIEW},
 		{Key: conf.OfficeViewers, Value: `{
 	"Microsoft":"https://view.officeapps.live.com/op/view.aspx?src=$url",
 	"Google":"https://docs.google.com/gview?url=$url&embedded=true",