diff --git a/scripts/riot b/scripts/riot
index 352d2cf..8b8c1b6 100755
--- a/scripts/riot
+++ b/scripts/riot
@@ -14,7 +14,7 @@ check_port() {
 
 # check if username valid
 check_username() {
-    ( echo $1 | grep -qxE "^[-.a-z0-9_]*\$" ) || return 1
+    ( echo $1 | grep -qxE "^[a-z][-a-z0-9_]*\$" ) || return 1
     return 0
 }