diff --git a/server_mc_manager.py b/server_mc_manager.py
index c217436..72ee28a 100644
--- a/server_mc_manager.py
+++ b/server_mc_manager.py
@@ -1,6 +1,7 @@
 import subprocess
 import shlex
 import time
+from typing import Union
 
 
 class MinecraftServerManager:
@@ -13,7 +14,7 @@ class MinecraftServerManager:
         self.cooldowns = {}
 
     def start_server(self, server_directory: str, port: int,
-                     java_executable='java', jar_file='server.jar', memory_size='2048M') -> int or None:
+                     java_executable='java', jar_file='server.jar', memory_size='2048M') -> Union[int, None]:
 
         if port in self.servers:
             return None