diff --git a/weed/server/filer_server_handlers_write_autochunk.go b/weed/server/filer_server_handlers_write_autochunk.go
index b990f6488..b44dc381a 100644
--- a/weed/server/filer_server_handlers_write_autochunk.go
+++ b/weed/server/filer_server_handlers_write_autochunk.go
@@ -59,6 +59,8 @@ func (fs *FilerServer) autoChunk(ctx context.Context, w http.ResponseWriter, r *
 	if err != nil {
 		if strings.HasPrefix(err.Error(), "read input:") {
 			writeJsonError(w, r, 499, err)
+		}else if strings.HasSuffix(err.Error(), "is a file") {
+			writeJsonError(w, r, http.StatusConflict, err)
 		} else {
 			writeJsonError(w, r, http.StatusInternalServerError, err)
 		}