diff --git a/MCSL2Lib/ServerControllers/windowCreator.py b/MCSL2Lib/ServerControllers/windowCreator.py
index 4111f23..fd81c64 100644
--- a/MCSL2Lib/ServerControllers/windowCreator.py
+++ b/MCSL2Lib/ServerControllers/windowCreator.py
@@ -361,6 +361,8 @@ def closeEvent(self, a0) -> None:
         del self
 
     def genRunScript(self, save=False):
+        if not hasattr(self.serverLauncher, 'jvmArg'):
+            self.serverLauncher._setJVMArg()
         script = (
             f"$host.ui.RawUI.WindowTitle=\"{self.serverConfig.serverName}\""
             f"\ncd \"{osp.abspath('Servers' + osp.sep + self.serverConfig.serverName)}\""