diff --git a/lib/filehandler.js b/lib/filehandler.js
index bab6f89..dfea3c4 100644
--- a/lib/filehandler.js
+++ b/lib/filehandler.js
@@ -10,6 +10,8 @@ module.exports = function (middleware, options) {
             if (redirect) {
                 files = {files: result};
                 res.redirect(redirect.replace(/%s/, encodeURIComponent(JSON.stringify(files))));
+            }else if(req.method == 'POST' && options.callback) {
+                options.callback(result, req, res);
             } else {
                 res.set({
                     'Content-Type': (req.headers.accept || '').indexOf('application/json') !== -1
diff --git a/lib/filemanager.js b/lib/filemanager.js
index d384c16..48c6986 100644
--- a/lib/filemanager.js
+++ b/lib/filemanager.js
@@ -60,7 +60,7 @@ module.exports = function (middleware, options) {
         fs.exists(dir + '/' + filename, function (exists) {
             if (exists) {
                 filename = filename.replace(/(?:(?: \(([\d]+)\))?(\.[^.]+))?$/, function (s, index, ext) {
-                    return ' (' + ((parseInt(index, 10) || 0) + 1) + ')' + (ext || '');
+                    return '_' + ((parseInt(index, 10) || 0) + 1) + (ext || '');
                 });
                 safeName(dir, filename, callback)
             } else {