diff --git a/check.sh b/check.sh
index 5fe708bf..180cf92c 100644
--- a/check.sh
+++ b/check.sh
@@ -1,4 +1,4 @@
 isort . --profile black --gitignore
 black . --extend-exclude "tl/(abcs|functions|types)/\w+.py"
 mypy --strict .
-pytest .
+pytest . -m "not net"
diff --git a/client/tests/client_test.py b/client/tests/client_test.py
index 82ddc4ba..2722860c 100644
--- a/client/tests/client_test.py
+++ b/client/tests/client_test.py
@@ -1,5 +1,6 @@
 import os
 import random
+from pytest import mark
 
 from telethon._impl.client.client.client import Client
 from telethon._impl.client.client.net import Config
@@ -7,6 +8,8 @@ from telethon._impl.session.message_box.defs import Session
 from telethon._impl.tl.mtproto import functions, types
 
 
+@mark.api
+@mark.net
 async def test_ping_pong() -> None:
     api_id = os.getenv("TG_ID")
     api_hash = os.getenv("TG_HASH")
diff --git a/client/tests/mtsender_test.py b/client/tests/mtsender_test.py
index 0ece35a8..99519f8b 100644
--- a/client/tests/mtsender_test.py
+++ b/client/tests/mtsender_test.py
@@ -1,7 +1,7 @@
 import asyncio
 import logging
 
-from pytest import LogCaptureFixture
+from pytest import LogCaptureFixture, mark
 from telethon._impl.mtproto.transport.full import Full
 from telethon._impl.mtsender.sender import connect
 from telethon._impl.tl import LAYER, abcs, functions, types
@@ -13,6 +13,7 @@ TELEGRAM_DEFAULT_TEST_DC = TELEGRAM_TEST_DC_2
 TEST_TIMEOUT = 10000
 
 
+@mark.net
 async def test_invoke_encrypted_method(caplog: LogCaptureFixture) -> None:
     caplog.set_level(logging.DEBUG)
 
diff --git a/pytest.ini b/pytest.ini
index 2f4c80e3..f7b6849f 100644
--- a/pytest.ini
+++ b/pytest.ini
@@ -1,2 +1,5 @@
 [pytest]
+markers =
+    net: performs network access
+    api: requires TG_ID and TG_HASH environment variables
 asyncio_mode = auto