diff --git a/core/api.go b/core/api.go
index a0054ef..179c51e 100644
--- a/core/api.go
+++ b/core/api.go
@@ -37,7 +37,7 @@ type FileDocumentDesc struct {
 	Contents  []byte `bson:"contents,omitempty" json:"contents,omitempty"`
 }
 
-func (fd *FileDocumentDesc) save() error {
+func (fd *FileDocumentDesc) Save() error {
 	// 새 파일 올라옴
 	if len(fd.Contents) == 0 {
 		return nil
diff --git a/core/maingate.go b/core/maingate.go
index 295d6f5..e176a8b 100644
--- a/core/maingate.go
+++ b/core/maingate.go
@@ -404,7 +404,7 @@ func (mg *Maingate) prepare(context context.Context) (err error) {
 		if err != nil {
 			return err
 		}
-		err = fulldoc.save()
+		err = fulldoc.Save()
 		if err != nil {
 			return err
 		}
diff --git a/core/watch.go b/core/watch.go
index ef22356..5da350e 100644
--- a/core/watch.go
+++ b/core/watch.go
@@ -213,7 +213,7 @@ func (mg *Maingate) watchFileCollection(parentctx context.Context, serveMux *htt
 		if err := stream.Decode(&data); err == nil {
 			switch data.OperationType {
 			case "insert":
-				data.File.save()
+				data.File.Save()
 
 			case "delete":
 				subfolder := hex.EncodeToString(data.DocumentKey.Id[:4])