diff --git a/src/requests/register.cr b/src/requests/register.cr
index 3b6eae7..d2cd36c 100644
--- a/src/requests/register.cr
+++ b/src/requests/register.cr
@@ -17,7 +17,7 @@ class AuthD::Request
 				return Response::ErrorAlreadyUsedLogin.new
 			end
 
-			acceptable_login_regex = "[a-zA-Z][a-zA-Z0-9 _-']+"
+			acceptable_login_regex = "[a-zA-Z][-_ a-zA-Z0-9']+"
 			pattern = Regex.new acceptable_login_regex, Regex::Options::IGNORE_CASE
 			return Response::ErrorInvalidLoginFormat.new unless pattern =~ @login