diff --git a/Makefile b/Makefile
index 5867514..d1d8772 100644
--- a/Makefile
+++ b/Makefile
@@ -9,6 +9,7 @@ docker-tests:
 	docker run --pull=always -v `pwd`:/app -w /app --rm -it python:3.10-alpine sh runtests.sh
 	docker run --pull=always -v `pwd`:/app -w /app --rm -it python:3.11 sh runtests.sh
 	docker run --pull=always -v `pwd`:/app -w /app --rm -it python:3.10 sh runtests.sh
+	docker run --pull=always -v `pwd`:/app -w /app --rm -it python:3.9 sh runtests.sh
 
 requirements.txt: Pipfile.lock
 	pipenv requirements > requirements.txt
diff --git a/mail4one/config.py b/mail4one/config.py
index 918bd85..1f97319 100644
--- a/mail4one/config.py
+++ b/mail4one/config.py
@@ -1,7 +1,7 @@
 import json
 import re
 import logging
-from typing import Callable
+from typing import Callable, Union, Optional
 from jata import Jata, MutableDefault
 
 
@@ -45,7 +45,7 @@ class ServerCfg(Jata):
     host: str = "default"
     port: int
     # disabled: bool = False
-    tls: TLSCfg | str = "default"
+    tls: Union[TLSCfg, str] = "default"
 
 
 class PopCfg(ServerCfg):
@@ -72,9 +72,9 @@ class LogCfg(Jata):
 
 
 class Config(Jata):
-    default_tls: TLSCfg | None
+    default_tls: Optional[TLSCfg] = None
     default_host: str = "0.0.0.0"
-    logging: LogCfg | None = None
+    logging: Optional[LogCfg] = None
 
     mails_path: str
     matches: list[Match]
diff --git a/mail4one/pop3.py b/mail4one/pop3.py
index 8d21b21..5b993ae 100644
--- a/mail4one/pop3.py
+++ b/mail4one/pop3.py
@@ -13,6 +13,8 @@ from .pwhash import parse_hash, check_pass, PWInfo
 from asyncio import StreamReader, StreamWriter
 import random
 
+from typing import Optional
+
 from .poputils import (
     InvalidCommand,
     parse_command,
@@ -361,7 +363,7 @@ async def create_pop_server(
     port: int,
     mails_path: Path,
     users: list[User],
-    ssl_context: ssl.SSLContext | None = None,
+    ssl_context: Optional[ssl.SSLContext] = None,
     timeout_seconds: int = 60,
 ) -> asyncio.Server:
     logging.info(
diff --git a/mail4one/server.py b/mail4one/server.py
index 72704ba..05e26c9 100644
--- a/mail4one/server.py
+++ b/mail4one/server.py
@@ -13,6 +13,7 @@ from .version import VERSION
 
 from . import config
 from . import pwhash
+from typing import Optional, Union
 
 
 def create_tls_context(certfile, keyfile) -> ssl.SSLContext:
@@ -34,13 +35,13 @@ def setup_logging(cfg: config.LogCfg):
 
 
 async def a_main(cfg: config.Config) -> None:
-    default_tls_context: ssl.SSLContext | None = None
+    default_tls_context: Optional[ssl.SSLContext] = None
 
     if tls := cfg.default_tls:
         logging.info(f"Initializing default tls {tls.certfile=}, {tls.keyfile=}")
         default_tls_context = create_tls_context(tls.certfile, tls.keyfile)
 
-    def get_tls_context(tls: config.TLSCfg | str):
+    def get_tls_context(tls: Union[config.TLSCfg, str]):
         if tls == "default":
             return default_tls_context
         elif tls == "disable":
diff --git a/mail4one/smtp.py b/mail4one/smtp.py
index 25ba5d6..fad36ce 100644
--- a/mail4one/smtp.py
+++ b/mail4one/smtp.py
@@ -7,7 +7,7 @@ import uuid
 import shutil
 from functools import partial
 from pathlib import Path
-from typing import Callable
+from typing import Callable, Optional
 from . import config
 from email.message import Message
 import email.policy
@@ -115,7 +115,7 @@ async def create_smtp_server(
     port: int,
     mails_path: Path,
     mbox_finder: Callable[[str], list[str]],
-    ssl_context: ssl.SSLContext | None = None,
+    ssl_context: Optional[ssl.SSLContext] = None,
 ) -> asyncio.Server:
     logging.info(
         f"Starting SMTP server {host=}, {port=}, {mails_path=!s}, {ssl_context != None=}"