diff --git a/src/VisualStudio/Core/Def/Implementation/ProjectSystem/CPS/AdditionalPropertyNames.cs b/src/VisualStudio/Core/Def/Implementation/ProjectSystem/CPS/AdditionalPropertyNames.cs
new file mode 100644
index 0000000000000000000000000000000000000000..b8982ea47d110fdaa211e73783e1ff60f7b0eb7f
--- /dev/null
+++ b/src/VisualStudio/Core/Def/Implementation/ProjectSystem/CPS/AdditionalPropertyNames.cs
@@ -0,0 +1,12 @@
+// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
+
+namespace Microsoft.VisualStudio.LanguageServices.ProjectSystem
+{
+    /// <summary>
+    /// A class that provides constants for common MSBuild property names.
+    /// </summary>
+    internal static class AdditionalPropertyNames
+    {
+        public const string RootNamespace = "rootnamespace";
+    }
+}
diff --git a/src/VisualStudio/Core/Def/Implementation/ProjectSystem/CPS/IWorkspaceProjectContext.cs b/src/VisualStudio/Core/Def/Implementation/ProjectSystem/CPS/IWorkspaceProjectContext.cs
index 11ea131841978f4aba18b0d9694776f2dd4c5f15..c917ae0851cdb1f9801c4f53e73a981a714f332a 100644
--- a/src/VisualStudio/Core/Def/Implementation/ProjectSystem/CPS/IWorkspaceProjectContext.cs
+++ b/src/VisualStudio/Core/Def/Implementation/ProjectSystem/CPS/IWorkspaceProjectContext.cs
@@ -23,6 +23,9 @@ internal interface IWorkspaceProjectContext : IDisposable
         // Options.
         void SetOptions(string commandLineForOptions);
 
+        // Other project properties.
+        void SetProperty(string name, string value);
+
         // References.
         void AddMetadataReference(string referencePath, MetadataReferenceProperties properties);
         void RemoveMetadataReference(string referencePath);
diff --git a/src/VisualStudio/Core/Impl/ProjectSystem/CPS/CPSProject_IWorkspaceProjectContext.cs b/src/VisualStudio/Core/Impl/ProjectSystem/CPS/CPSProject_IWorkspaceProjectContext.cs
index 0c1f16ffe4d4b57e5aa018bef514335a14d39abd..c4284c508206329654d0fb3eda8aa86f5046077c 100644
--- a/src/VisualStudio/Core/Impl/ProjectSystem/CPS/CPSProject_IWorkspaceProjectContext.cs
+++ b/src/VisualStudio/Core/Impl/ProjectSystem/CPS/CPSProject_IWorkspaceProjectContext.cs
@@ -133,6 +133,11 @@ public void SetOptions(string commandLineForOptions)
             }
         }
 
+        public void SetProperty(string name, string value)
+        {
+            // TODO
+        }
+
         public void AddMetadataReference(string referencePath, MetadataReferenceProperties properties)
         {
             referencePath = FileUtilities.NormalizeAbsolutePath(referencePath);