diff --git a/index.php b/index.php
index 79cfb78..4883728 100644
--- a/index.php
+++ b/index.php
@@ -34,7 +34,7 @@
 
 	<div id="login_pane">
 		<form method="post">
-			<div>Uživatelské jméno: <input type="text" maxlength="32" name="username" required><br></div>
+			<div>Uživatelské jméno: <input type="text" minlength="4" maxlength="32" name="username" required><br></div>
 			<div>Heslo: <input type="text" name="password" required><br></div>
 			<div id="sub_btn_div"><input id="sub_btn" type="submit" name="sub"></div>
 		</form>