diff --git a/src/Netclaw.Actors.Tests/Sessions/SessionLogActorTests.cs b/src/Netclaw.Actors.Tests/Sessions/SessionLogActorTests.cs
index c448e3124..69c66e429 100644
--- a/src/Netclaw.Actors.Tests/Sessions/SessionLogActorTests.cs
+++ b/src/Netclaw.Actors.Tests/Sessions/SessionLogActorTests.cs
@@ -201,9 +201,13 @@ public async Task Dispatcher_writes_audit_and_diagnostic_to_same_session_log()
         {
             var dispatcher = SpawnDispatcher(Sys, basePath, timeProvider);
 
-            dispatcher.Tell(new TextOutput("audit-line") { SessionId = sessionId }, ActorRefs.NoSender);
+            // Buffered diagnostic first; the durable audit write below drains
+            // it synchronously (SessionLogActor.WriteDurable) — no dependence
+            // on the 1s FlushTick wall-clock timer, which is what made this
+            // test flaky on loaded Windows CI runners.
             timeProvider.Advance(TimeSpan.FromMilliseconds(1));
             dispatcher.Tell(new SessionLogDiagnostic(sessionId, "[2026-05-07T13:30:00.001+00:00] Diagnostic: provider sent request"), ActorRefs.NoSender);
+            dispatcher.Tell(new TextOutput("audit-line") { SessionId = sessionId }, ActorRefs.NoSender);
 
             await AwaitAssertAsync(async () =>
             {