diff --git a/cmdeploy/src/cmdeploy/tests/online/test_1_basic.py b/cmdeploy/src/cmdeploy/tests/online/test_1_basic.py
index 60c3987d..438d57e4 100644
--- a/cmdeploy/src/cmdeploy/tests/online/test_1_basic.py
+++ b/cmdeploy/src/cmdeploy/tests/online/test_1_basic.py
@@ -255,6 +255,7 @@ def test_rewrite_subject(cmsetup, maildata):
     assert "Subject: Unencrypted subject" not in rcvd_msg
 
 
+@pytest.mark.xdist_group(name="serial_relay_state")
 def test_exceed_rate_limit(cmsetup, gencreds, maildata, chatmail_config):
     """Test that the per-account send-mail limit is exceeded."""
     user1, user2 = cmsetup.gen_users(2)
@@ -277,6 +278,7 @@ def test_exceed_rate_limit(cmsetup, gencreds, maildata, chatmail_config):
     pytest.fail("Rate limit was not exceeded")
 
 
+@pytest.mark.xdist_group(name="serial_relay_state")
 def test_expunged(remote, chatmail_config):
     outdated_days = int(chatmail_config.delete_mails_after) + 1
     find_cmds = [
diff --git a/cmdeploy/src/cmdeploy/tests/online/test_2_deltachat.py b/cmdeploy/src/cmdeploy/tests/online/test_2_deltachat.py
index f15f006a..8c48c15c 100644
--- a/cmdeploy/src/cmdeploy/tests/online/test_2_deltachat.py
+++ b/cmdeploy/src/cmdeploy/tests/online/test_2_deltachat.py
@@ -79,6 +79,7 @@ class TestEndToEndDeltaChat:
         msg2 = ac2.wait_for_incoming_msg()
         assert msg2.get_snapshot().text == "message0"
 
+    @pytest.mark.xdist_group(name="serial_relay_state")
     def test_exceed_quota(
         self, cmfactory, lp, tmpdir, remote, chatmail_config, sshdomain
     ):