1 files changed, 11 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..1b6f3aff7a
--- /dev/null
+++ b/src/mscorlib/src/System/Collections/IStructuralComparable.cs
@@ -0,0 +1,11 @@
+// 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.Collections {
+
+    public interface IStructuralComparable {
+        Int32 CompareTo(Object other, IComparer comparer);
+    }
+}