diff --git a/playground/Stress/Stress.ApiService/Program.cs b/playground/Stress/Stress.ApiService/Program.cs
index 086e6fafb9c..bcf9429ebbe 100644
--- a/playground/Stress/Stress.ApiService/Program.cs
+++ b/playground/Stress/Stress.ApiService/Program.cs
@@ -225,4 +225,16 @@ async IAsyncEnumerable<string> WriteOutput()
     return "Log with formatted data";
 });
 
+app.MapGet("/duplicate-spanid", async () =>
+{
+    var traceCreator = new TraceCreator();
+    var span1 = traceCreator.CreateActivity("Test 1", "0485b1947fe788bb");
+    await Task.Delay(1000);
+    span1?.Stop();
+    var span2 = traceCreator.CreateActivity("Test 2", "0485b1947fe788bb");
+    await Task.Delay(1000);
+    span2?.Stop();
+    return $"Created duplicate span IDs.";
+});
+
 app.Run();
diff --git a/playground/Stress/Stress.ApiService/TraceCreator.cs b/playground/Stress/Stress.ApiService/TraceCreator.cs
index 5a7accc699d..c8b08c60a8e 100644
--- a/playground/Stress/Stress.ApiService/TraceCreator.cs
+++ b/playground/Stress/Stress.ApiService/TraceCreator.cs
@@ -2,6 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System.Diagnostics;
+using System.Reflection;
 
 namespace Stress.ApiService;
 
@@ -13,6 +14,22 @@ public class TraceCreator
 
     private readonly List<Activity> _allActivities = new List<Activity>();
 
+    public Activity? CreateActivity(string name, string? spandId)
+    {
+        var activity = s_activitySource.StartActivity(name, ActivityKind.Client);
+        if (activity != null)
+        {
+            if (spandId != null)
+            {
+                // Gross but it's the only way.
+                typeof(Activity).GetField("_spanId", BindingFlags.Instance | BindingFlags.NonPublic)!.SetValue(activity, spandId);
+                typeof(Activity).GetField("_traceId", BindingFlags.Instance | BindingFlags.NonPublic)!.SetValue(activity, activity.TraceId.ToString());
+            }
+        }
+
+        return activity;
+    }
+
     public async Task CreateTraceAsync(int count, bool createChildren)
     {
         var activityStack = new Stack<Activity>();