diff --git a/cs/remote/samples/FixedLenServer/Types.cs b/cs/remote/samples/FixedLenServer/Types.cs
index f742fd7f5..aa7fa2a33 100644
--- a/cs/remote/samples/FixedLenServer/Types.cs
+++ b/cs/remote/samples/FixedLenServer/Types.cs
@@ -65,7 +65,7 @@ public void UpsertCompletionCallback(ref Key key, ref Input input, ref Value val
         public void DeleteCompletionCallback(ref Key key, long ctx) { }
 
         public void CheckpointCompletionCallback(int sessionID, string sessionName, CommitPoint commitPoint)
-            => Debug.WriteLine("Session {0} reports persistence until {1}", sessionID, commitPoint.UntilSerialNo);
+            => Debug.WriteLine($"Session {sessionID} ({(sessionName ?? "null")}) reports persistence until {commitPoint.UntilSerialNo}");
 
         // Read functions
         [MethodImpl(MethodImplOptions.AggressiveInlining)]