diff --git a/dotnet/tests/Microsoft.Agents.AI.Workflows.UnitTests/InputWaiterAndOutputFilterTests.cs b/dotnet/tests/Microsoft.Agents.AI.Workflows.UnitTests/InputWaiterAndOutputFilterTests.cs
index 55f02db443..77c0160200 100644
--- a/dotnet/tests/Microsoft.Agents.AI.Workflows.UnitTests/InputWaiterAndOutputFilterTests.cs
+++ b/dotnet/tests/Microsoft.Agents.AI.Workflows.UnitTests/InputWaiterAndOutputFilterTests.cs
@@ -28,6 +28,7 @@ public sealed class InputWaiterTests : IDisposable
         Task completed = await Task.WhenAny(waitTask, Task.Delay(TimeSpan.FromSeconds(1)));
 
         completed.Should().BeSameAs(waitTask, "the wait task should complete before the timeout");
+        await waitTask;
     }
 
     [Fact]
@@ -42,6 +43,7 @@ public sealed class InputWaiterTests : IDisposable
 
         Task completed = await Task.WhenAny(waitTask, Task.Delay(TimeSpan.FromSeconds(1)));
         completed.Should().BeSameAs(waitTask, "the wait task should complete after being signaled");
+        await waitTask;
     }
 
     [Fact]
diff --git a/dotnet/tests/Microsoft.Agents.AI.Workflows.UnitTests/RoundRobinGroupChatManagerTests.cs b/dotnet/tests/Microsoft.Agents.AI.Workflows.UnitTests/RoundRobinGroupChatManagerTests.cs
index d1c545f202..3c87507ec6 100644
--- a/dotnet/tests/Microsoft.Agents.AI.Workflows.UnitTests/RoundRobinGroupChatManagerTests.cs
+++ b/dotnet/tests/Microsoft.Agents.AI.Workflows.UnitTests/RoundRobinGroupChatManagerTests.cs
@@ -126,7 +126,8 @@ public class RoundRobinGroupChatManagerTests
     public void RoundRobinGroupChat_Constructor_ThrowsOnNullAgents()
     {
         FluentActions.Invoking(() => new RoundRobinGroupChatManager(null!))
-            .Should().Throw<System.ArgumentException>();
+            .Should().Throw<System.ArgumentNullException>()
+            .WithParameterName("agents");
     }
 
     [Fact]