1 files changed, 18 insertions, 0 deletions
diff --git a/src/mscorlib/src/System/Runtime/CompilerServices/AsyncStateMachineAttribute.cs b/src/mscorlib/src/System/Runtime/CompilerServices/AsyncStateMachineAttribute.cs
new file mode 100644
index 0000000000..f1fc9ced82
--- /dev/null
+++ b/src/mscorlib/src/System/Runtime/CompilerServices/AsyncStateMachineAttribute.cs
@@ -0,0 +1,18 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+
+using System;
+
+namespace System.Runtime.CompilerServices
+{
+    [Serializable, AttributeUsage(AttributeTargets.Method, Inherited = false, AllowMultiple = false)]
+    public sealed class AsyncStateMachineAttribute : StateMachineAttribute
+    {
+        public AsyncStateMachineAttribute(Type stateMachineType)
+            : base(stateMachineType)
+        {
+        }
+    }
+}