diff --git a/src/Persistence/Wolverine.Marten/FlushOutgoingMessagesOnCommit.cs b/src/Persistence/Wolverine.Marten/FlushOutgoingMessagesOnCommit.cs
index 16d7236a2..54360e364 100644
--- a/src/Persistence/Wolverine.Marten/FlushOutgoingMessagesOnCommit.cs
+++ b/src/Persistence/Wolverine.Marten/FlushOutgoingMessagesOnCommit.cs
@@ -1,6 +1,7 @@
 using Marten;
 using Marten.Services;
 using Wolverine.Marten.Persistence.Operations;
+using Wolverine.Persistence.Durability;
 using Wolverine.Postgresql;
 using Wolverine.RDBMS;
 using Wolverine.Runtime;
@@ -25,27 +26,36 @@ public override Task BeforeSaveChangesAsync(IDocumentSession session, Cancellati
         {
             return Task.CompletedTask;
         }
-        
+
         // Mark as handled!
         if (_context.Envelope.Destination != null)
         {
             if (_context.Envelope.WasPersistedInInbox)
             {
+                // GH-2155: When using ancillary stores (e.g., [MartenStore]), the incoming
+                // envelope was persisted in the main store by DurableReceiver. We should only
+                // mark it as handled within this Marten session if the session's store is
+                // the same store. Otherwise, let DurableReceiver handle it via the main store.
+                if (_context.Envelope.Store == null && _messageStore.Role == MessageStoreRole.Ancillary)
+                {
+                    return Task.CompletedTask;
+                }
+
                 var keepUntil = DateTimeOffset.UtcNow.Add(_context.Runtime.Options.Durability.KeepAfterMessageHandling);
                 session.QueueSqlCommand($"update {_messageStore.IncomingFullName} set {DatabaseConstants.Status} = '{EnvelopeStatus.Handled}', {DatabaseConstants.KeepUntil} = ? where id = ?", keepUntil, _context.Envelope.Id);
                 _context.Envelope.Status = EnvelopeStatus.Handled;
             }
-            
-            // This was buggy in real usage. 
+
+            // This was buggy in real usage.
             // else
             // {
             //     var envelope = Envelope.ForPersistedHandled(_context.Envelope, DateTimeOffset.UtcNow, _context.Runtime.Options.Durability);
             //     session.QueueOperation(new StoreIncomingEnvelope(_messageStore.IncomingFullName, envelope));
             // }
-            
-            
+
+
         }
-        
+
         return Task.CompletedTask;
     }
 
diff --git a/src/Transports/RabbitMQ/Wolverine.RabbitMQ.Tests/Bugs/Bug_2155_ancillary_store_inbox_persistence.cs b/src/Transports/RabbitMQ/Wolverine.RabbitMQ.Tests/Bugs/Bug_2155_ancillary_store_inbox_persistence.cs
new file mode 100644
index 000000000..83092bd98
--- /dev/null
+++ b/src/Transports/RabbitMQ/Wolverine.RabbitMQ.Tests/Bugs/Bug_2155_ancillary_store_inbox_persistence.cs
@@ -0,0 +1,109 @@
+using IntegrationTests;
+using JasperFx.Core;
+using JasperFx.Resources;
+using Marten;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Hosting;
+using Shouldly;
+using Wolverine.Attributes;
+using Wolverine.Marten;
+using Wolverine.Persistence.Durability;
+using Wolverine.Runtime;
+using Wolverine.Util;
+using Wolverine.Tracking;
+using Xunit;
+
+namespace Wolverine.RabbitMQ.Tests.Bugs;
+
+public interface IAncillaryStore2155 : IDocumentStore;
+
+public record AncillaryMessage2155(Guid Id);
+
+[MartenStore(typeof(IAncillaryStore2155))]
+public static class AncillaryMessage2155Handler
+{
+    [Transactional]
+    public static void Handle(AncillaryMessage2155 message, IDocumentSession session)
+    {
+        // Just touch the session so the transactional middleware commits
+        session.Store(new AncillaryDoc2155 { Id = message.Id });
+    }
+}
+
+public class AncillaryDoc2155
+{
+    public Guid Id { get; set; }
+}
+
+public class Bug_2155_ancillary_store_inbox_persistence : IAsyncLifetime
+{
+    private IHost _host;
+    private string _queueName;
+
+    public async Task InitializeAsync()
+    {
+        _queueName = RabbitTesting.NextQueueName();
+
+        _host = await Host.CreateDefaultBuilder()
+            .UseWolverine(opts =>
+            {
+                opts.Durability.Mode = DurabilityMode.Solo;
+
+                // Main Marten store
+                opts.Services.AddMarten(m =>
+                {
+                    m.Connection(Servers.PostgresConnectionString);
+                    m.DatabaseSchemaName = "bug2155_main";
+                    m.DisableNpgsqlLogging = true;
+                }).IntegrateWithWolverine(x => x.MessageStorageSchemaName = "bug2155_main");
+
+                // Ancillary Marten store on same database but different schema
+                opts.Services.AddMartenStore<IAncillaryStore2155>(m =>
+                {
+                    m.Connection(Servers.PostgresConnectionString);
+                    m.DatabaseSchemaName = "bug2155_ancillary";
+                    m.DisableNpgsqlLogging = true;
+                }).IntegrateWithWolverine(x => x.SchemaName = "bug2155_ancillary");
+
+                opts.UseRabbitMq().AutoProvision().AutoPurgeOnStartup();
+
+                opts.PublishMessage<AncillaryMessage2155>().ToRabbitQueue(_queueName).UseDurableOutbox();
+                opts.ListenToRabbitQueue(_queueName).UseDurableInbox();
+
+                opts.Policies.AutoApplyTransactions();
+
+                opts.Services.AddResourceSetupOnStartup();
+            }).StartAsync();
+
+        await _host.ResetResourceState();
+    }
+
+    public async Task DisposeAsync()
+    {
+        await _host.StopAsync();
+        _host.Dispose();
+    }
+
+    [Fact]
+    public async Task incoming_envelope_should_be_marked_as_handled_in_main_store()
+    {
+        var message = new AncillaryMessage2155(Guid.NewGuid());
+
+        await _host
+            .TrackActivity()
+            .IncludeExternalTransports()
+            .SendMessageAndWaitAsync(message);
+
+        // Give a moment for the async mark-as-handled to complete
+        await Task.Delay(500);
+
+        // The main store should have the envelope marked as Handled (not stuck as Incoming)
+        var runtime = _host.GetRuntime();
+        var incoming = await runtime.Storage.Admin.AllIncomingAsync();
+        var stuck = incoming.Where(x =>
+            x.MessageType == typeof(AncillaryMessage2155).ToMessageTypeName()
+            && x.Status == EnvelopeStatus.Incoming).ToList();
+
+        stuck.ShouldBeEmpty("Incoming envelopes should not be stuck in 'Incoming' status in the main store");
+    }
+}