diff --git a/test/Microsoft.AspNet.Mvc.Razor.Host.Test/TestFileSystem.cs b/test/Microsoft.AspNet.Mvc.Razor.Host.Test/TestFileSystem.cs
index 68b2a58644..ffdc97b3a1 100644
--- a/test/Microsoft.AspNet.Mvc.Razor.Host.Test/TestFileSystem.cs
+++ b/test/Microsoft.AspNet.Mvc.Razor.Host.Test/TestFileSystem.cs
@@ -41,5 +41,10 @@ namespace Microsoft.AspNet.Mvc.Razor
         {
             return _lookup.TryGetValue(subpath, out fileInfo);
         }
+
+        public bool TryGetParentPath(string subpath, out string parentPath)
+        {
+            throw new NotImplementedException();
+        }
     }
 }
\ No newline at end of file