diff --git a/tests/gateway/test_restart_drain.py b/tests/gateway/test_restart_drain.py
index 844af427308..9000e4d4820 100644
--- a/tests/gateway/test_restart_drain.py
+++ b/tests/gateway/test_restart_drain.py
@@ -33,7 +33,16 @@ async def test_restart_command_while_busy_requests_drain_without_interrupt(monke
 
     result = await runner._handle_message(event)
 
-    assert result == t("gateway.draining", count=1)
+    expected = t("gateway.draining", count=1)
+    assert result == expected
+    # Guard against the silent-degradation regression in #22266: if the i18n
+    # catalog cannot be resolved (e.g. xdist workers losing the locales path)
+    # then ``t("gateway.draining", count=1)`` returns the bare key
+    # ``"gateway.draining"`` instead of the formatted English string, and both
+    # sides of the equality above would still match. Assert on the catalog
+    # output explicitly so a broken locale resolution fails loudly here.
+    assert expected != "gateway.draining"
+    assert "Draining" in expected and "1" in expected
     running_agent.interrupt.assert_not_called()
     runner.request_restart.assert_called_once_with(detached=True, via_service=False)