diff --git a/lib/helpers.js b/lib/helpers.js
index d863a24..120afa3 100644
--- a/lib/helpers.js
+++ b/lib/helpers.js
@@ -8,7 +8,7 @@ var path = require("path");
 var fs = require("fs");
 
 // 0098cb60-fa8e-427c-b299-793cbd302c9a
-var valid_user_id = /^[0-9a-f-A-F-]{32,36}$/; // uuid
+var valid_user_id = /^[0-9a-fA-F\-]{32,36}$/; // uuid
 var hash_pattern = /[0-9a-f]+$/;
 
 // gets the hash from the textures.minecraft.net +url+