diff --git a/pymodbus/server/server.py b/pymodbus/server/server.py
index 004e06f60..d2cd1d2ae 100644
--- a/pymodbus/server/server.py
+++ b/pymodbus/server/server.py
@@ -117,6 +117,10 @@ def __init__(
         :param trace_connect: Called when connected/disconnected
         :param custom_pdu: list of ModbusPDU custom classes
         """
+        if not sslctx:
+            raise TypeError(
+                "Cannot start server without a certificate, please add sslctx="
+            )
         self.tls_setup = CommParams(
             comm_type=CommType.TLS,
             comm_name="server_listener",
diff --git a/test/server/test_server_asyncio.py b/test/server/test_server_asyncio.py
index 5b577b1a8..21083c76a 100755
--- a/test/server/test_server_asyncio.py
+++ b/test/server/test_server_asyncio.py
@@ -10,6 +10,7 @@
 
 import pytest
 
+from examples.helper import generate_ssl, get_certificate
 from pymodbus import FramerType, ModbusDeviceIdentification
 from pymodbus.exceptions import NoSuchIdException
 from pymodbus.server import (
@@ -162,6 +163,11 @@ async def start_server(
                 framer=FramerType.TLS,
                 identity=self.identity,
                 address=serv_addr,
+                sslctx=generate_ssl(
+                    False,
+                    certfile=get_certificate("crt"),
+                    keyfile=get_certificate("key"),
+                ),
             )
         elif do_udp:
             self.server = ModbusUdpServer(
diff --git a/test/server/test_startstop.py b/test/server/test_startstop.py
index 485b09c6c..ecf4da528 100755
--- a/test/server/test_startstop.py
+++ b/test/server/test_startstop.py
@@ -6,6 +6,7 @@
 
 import pytest
 
+from examples.helper import generate_ssl, get_certificate
 from pymodbus.datastore import ModbusDeviceContext, ModbusServerContext
 from pymodbus.server import (
     ModbusBaseServer,
@@ -59,9 +60,23 @@ async def test_StartAsyncTlsServer(self, mock_method):
         """Test  StartAsyncTlsServer."""
         mock_method.return_value = True
         await StartAsyncTlsServer(
-            ModbusServerContext(devices=ModbusDeviceContext(), single=True)
+            ModbusServerContext(devices=ModbusDeviceContext(), single=True),
+            sslctx=generate_ssl(
+                False,
+                certfile=get_certificate("crt"),
+                keyfile=get_certificate("key"),
+            ),
         )
 
+    @mock.patch("pymodbus.server.ModbusBaseServer.serve_forever")
+    async def test_tls_no_cert(self, mock_method):
+        """Test  StartAsyncTlsServer."""
+        mock_method.return_value = True
+        with pytest.raises(TypeError):
+            await StartAsyncTlsServer(
+                ModbusServerContext(devices=ModbusDeviceContext(), single=True),
+            )
+
     @mock.patch("pymodbus.server.ModbusBaseServer.serve_forever")
     async def test_StartAsyncUdpServer(self, mock_method):
         """Test  StartAsyncUdpServer."""
@@ -104,7 +119,14 @@ def test_StartTcpServer(self, mock_method):
     def test_StartTlsServer(self, mock_method):
         """Test  StartTlsServer."""
         mock_method.return_value = True
-        StartTlsServer(ModbusServerContext(devices=ModbusDeviceContext(), single=True))
+        StartTlsServer(
+            ModbusServerContext(devices=ModbusDeviceContext(), single=True),
+            sslctx=generate_ssl(
+                False,
+                certfile=get_certificate("crt"),
+                keyfile=get_certificate("key"),
+            ),
+        )
 
     @mock.patch("pymodbus.server.ModbusBaseServer.serve_forever")
     def test_StartUdpServer(self, mock_method):