diff --git a/src/game.cpp b/src/game.cpp
index 4d4d67a6853..af139596fef 100644
--- a/src/game.cpp
+++ b/src/game.cpp
@@ -1384,7 +1384,7 @@ bool game_controller::play_multiplayer()
 	{
 		gui::dialog d(disp(), _("Multiplayer"), "", gui::OK_CANCEL);
 		d.set_menu(host_or_join);
-		d.set_textbox(_("Login: "), login, 18, font::relative_size(250));
+		d.set_textbox(_("Login: "), login, mp::max_login_size, font::relative_size(250));
 		res = d.show();
 		login = d.textbox_text();
 	}
diff --git a/src/multiplayer.cpp b/src/multiplayer.cpp
index cde61060021..0028e34ce71 100644
--- a/src/multiplayer.cpp
+++ b/src/multiplayer.cpp
@@ -228,11 +228,11 @@ static server_type open_connection(game_display& disp, const std::string& origin
 				if(!first_time) {
 					const int res = gui::show_dialog(disp, NULL, "",
 							_("You must log in to this server"), gui::OK_CANCEL,
-							NULL, NULL, _("Login: "), &login, 18);
+							NULL, NULL, _("Login: "), &login, mp::max_login_size);
 					if(res != 0 || login.empty()) {
 						return ABORT_SERVER;
 					}
-					if(login.size() > 18) {
+					if(login.size() > mp::max_login_size) {
 						gui::show_error_message(disp, _("The login name you chose is too long, please use a login with less than 18 characters"));
 						return ABORT_SERVER;
 					}
diff --git a/src/multiplayer.hpp b/src/multiplayer.hpp
index 49b2df4326e..ddc57ea0c8d 100644
--- a/src/multiplayer.hpp
+++ b/src/multiplayer.hpp
@@ -21,6 +21,9 @@ class game_data;
 
 namespace mp {
 
+// max. length of a player name
+const int max_login_size = 18;
+
 /*
  * This is the main entry points of multiplayer mode.
  */