diff --git a/src/routes/validate/user.ts b/src/routes/validate/user.ts
index 4472aa8..c146d7e 100644
--- a/src/routes/validate/user.ts
+++ b/src/routes/validate/user.ts
@@ -5,9 +5,9 @@ import IdValidate from './id';
 
 export default class UserValidate {  // validate input for user
   private static user = {
-    name: Joi.string()  // TODO: check allowed characters
-      .alphanum()
+    name: Joi.string()
       .lowercase()
+      .pattern(new RegExp('^[a-z0-9-_.]+$'))
       .max(128),
 
     email: Joi.string()