1 files changed, 10 insertions, 0 deletions
diff --git a/src/mscorlib/src/System/Collections/IStructuralComparable.cs b/src/mscorlib/src/System/Collections/IStructuralComparable.cs
new file mode 100644
index 0000000000..175cc48a2d
--- /dev/null
+++ b/src/mscorlib/src/System/Collections/IStructuralComparable.cs
@@ -0,0 +1,10 @@
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+using System;
+
+namespace System.Collections {
+
+    public interface IStructuralComparable {
+        Int32 CompareTo(Object other, IComparer comparer);
+    }
+}