diff --git a/src/web/js/lib/account_validator.js b/src/web/js/lib/account_validator.js
index 60f6960..88b456e 100644
--- a/src/web/js/lib/account_validator.js
+++ b/src/web/js/lib/account_validator.js
@@ -1,5 +1,5 @@
 function AccountValidator() {
-	this.patternMaestroID = /^[A-Za-z가-힣]{1}[A-Za-z0-9가-힣]{2,19}$/;
+	this.patternMaestroID = /^[A-Za-z가-힣]{1}[A-Za-z0-9가-힣]{3,19}$/;
 	this.patternMaestroPW = /^[A-Za-z0-9]{4,16}$/;
 
 	this.patternPlayerID = /^[A-Za-z0-9가-힣-_]{1,8}$/;