diff --git a/src/SourceBuild/content/eng/tools/tasks/Microsoft.DotNet.SourceBuild.Tasks.XPlat/AddRidToRuntimeJson.cs b/src/SourceBuild/content/eng/tools/tasks/Microsoft.DotNet.SourceBuild.Tasks.XPlat/AddRidToRuntimeJson.cs
deleted file mode 100644
index 5842d0d82..000000000
--- a/src/SourceBuild/content/eng/tools/tasks/Microsoft.DotNet.SourceBuild.Tasks.XPlat/AddRidToRuntimeJson.cs
+++ /dev/null
@@ -1,94 +0,0 @@
-// 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;
-using System.IO;
-using System.Text;
-using Microsoft.Build.Framework;
-using Microsoft.Build.Utilities;
-using NuGet.Packaging;
-using NuGet.Packaging.Core;
-using Newtonsoft.Json;
-using Newtonsoft.Json.Linq;
-using System.Collections.Generic;
-using System.Linq;
-using NuGet.Versioning;
-
-namespace Microsoft.DotNet.Build.Tasks
-{
-    public class AddRidToRuntimeJson:Task
-    {
-        /// <summary>
-        /// [OS name].[version]-[architecture]
-        /// </summary>
-        [Required]
-        public string Rid { get; set; }
-
-        [Required]
-        public string RuntimeJson { get; set; }
-
-        private string runtimesIdentifier = "runtimes";
-
-        public override bool Execute()
-        {
-            string[] ridParts = Rid.Split('-');
-            string osNameAndVersion = ridParts[0];
-            string[] osParts = osNameAndVersion.Split(new char[] { '.' }, 2);
-
-            if (ridParts.Length < 1 || osParts.Length < 2)
-            {
-                throw new System.InvalidOperationException($"Unknown rid format {Rid}.");
-            }
-
-            // Acquire Rid parts:
-            //   osName
-            //   version
-            //   arch
-            string arch = ridParts[1];
-            string osName = osParts[0];
-            string version = osParts[1];
-
-            JObject projectRoot = ReadProject(RuntimeJson);
-
-            if (projectRoot.SelectToken($"{runtimesIdentifier}.{osName}") == null)
-            {
-                AddRidToRuntimeGraph(projectRoot, osName, "linux");
-                AddRidToRuntimeGraph(projectRoot, $"{osName}-{arch}", osName, $"linux-{arch}");
-            }
-            if(projectRoot.SelectToken($"{runtimesIdentifier}.{osName}.{version}") == null)
-            { 
-                AddRidToRuntimeGraph(projectRoot, $"{osName}.{version}", osName);
-                AddRidToRuntimeGraph(projectRoot, $"{osName}.{version}-{arch}", $"{osName}.{version}", $"{osName}-{arch}");
-            }
-
-            WriteProject(projectRoot, RuntimeJson);
-            return true;
-        }
-
-        private void AddRidToRuntimeGraph(JObject projectRoot, string name, params string[] imports)
-        {
-            projectRoot[runtimesIdentifier][name] = new JObject(new JProperty("#import", new JArray(imports)));
-        }
-
-        private static JObject ReadProject(string projectJsonPath)
-        {
-            using (TextReader projectFileReader = File.OpenText(projectJsonPath))
-            {
-                var projectJsonReader = new JsonTextReader(projectFileReader);
-                var serializer = new JsonSerializer();
-                return serializer.Deserialize<JObject>(projectJsonReader);
-            }
-        }
-        private static void WriteProject(JObject projectRoot, string projectJsonPath)
-        {
-            string projectJson = JsonConvert.SerializeObject(projectRoot, Formatting.Indented) + Environment.NewLine;
-
-            if (!File.Exists(projectJsonPath) || !projectJson.Equals(File.ReadAllText(projectJsonPath)))
-            {
-                Directory.CreateDirectory(Path.GetDirectoryName(projectJsonPath));
-                File.WriteAllText(projectJsonPath, projectJson);
-            }
-        }
-    }
-}
diff --git a/src/SourceBuild/content/repo-projects/Directory.Build.targets b/src/SourceBuild/content/repo-projects/Directory.Build.targets
index 8499e90dd..baaa8cf59 100644
--- a/src/SourceBuild/content/repo-projects/Directory.Build.targets
+++ b/src/SourceBuild/content/repo-projects/Directory.Build.targets
@@ -543,8 +543,8 @@
       <ReferencePackageFiles Include="$(ReferencePackagesDir)**/*.nupkg" />
 
       <!-- Check all RIDs from all restored Microsoft.NETCore.Platforms packages. -->
-      <PlatformsRuntimeJsonFiles Include="$(LocalNuGetPackagesRoot)*/microsoft.netcore.platforms/*/runtime.json" />
-      <PlatformsRuntimeJsonFiles Include="$(PackagesDir)microsoft.netcore.platforms/*/runtime.json" />
+      <PlatformsRuntimeJsonFiles Include="$(LocalNuGetPackagesRoot)*/microsoft.netcore.platforms/*/PortableRuntimeIdentifierGraph.json" />
+      <PlatformsRuntimeJsonFiles Include="$(PackagesDir)microsoft.netcore.platforms/*/PortableRuntimeIdentifierGraph.json" />
 
       <!-- Add some other potential top-level project directories for a more specific report. -->
       <ProjectDirectories Include="$(SourceBuiltSdksDir);$(TaskDirectory);$(BaseIntermediatePath)" />
diff --git a/src/SourceBuild/content/repo-projects/runtime.proj b/src/SourceBuild/content/repo-projects/runtime.proj
index e9146e0a3..f68566967 100644
--- a/src/SourceBuild/content/repo-projects/runtime.proj
+++ b/src/SourceBuild/content/repo-projects/runtime.proj
@@ -16,7 +16,7 @@
     <RuntimeOS>$(NETCoreSdkRuntimeIdentifier.Substring(0, $(_platformIndex)))</RuntimeOS>
 
     <_platformIndex>$(NETCoreSdkPortableRuntimeIdentifier.LastIndexOf('-'))</_platformIndex>
-    <BaseOS>$(NETCoreSdkPortableRuntimeIdentifier.Substring(0, $(_platformIndex)))</BaseOS>
+    <BaseOS>$(NETCoreSdkPortableRuntimeIdentifier.Substring(0, $(_platformIndex)))-$(Platform)</BaseOS>
 
     <PortableBuild Condition="'$(PortableBuild)' == ''">false</PortableBuild>
     <BuildNonPortable>true</BuildNonPortable>
@@ -54,8 +54,6 @@
       <RepositoryReference Include="source-build-externals" />
   </ItemGroup>
 
-  <UsingTask AssemblyFile="$(XPlatSourceBuildTasksAssembly)" TaskName="AddRidToRuntimeJson" />
-
   <Target Name="SetOutputList" AfterTargets="Package" BeforeTargets="GatherBuiltPackages">
     <ItemGroup>
       <PackagesOutputList Include="$(ShippingPackagesOutput)" />
@@ -63,17 +61,5 @@
     </ItemGroup>
   </Target>
 
-  <Target Name="UpdateRuntimeGraph"
-          BeforeTargets="Build"
-          Condition="'$(_IsBootstrapping)' == 'true'">
-    <PropertyGroup>
-      <RuntimeJsonFile>$(ProjectDirectory)pkg/Microsoft.NETCore.Platforms/runtime.json</RuntimeJsonFile>
-    </PropertyGroup>
-
-    <Message Importance="High" Text="Adding rid, $(TargetRid), to $(RuntimeJsonFile)" />
-    <AddRidToRuntimeJson RuntimeJson="$(RuntimeJsonFile)"
-                         Rid="$(TargetRid)-$(Platform)" />
-  </Target>
-
   <Import Project="Sdk.targets" Sdk="Microsoft.NET.Sdk" />
 </Project>
diff --git a/src/redist/targets/GenerateBundledVersions.targets b/src/redist/targets/GenerateBundledVersions.targets
index 3332b4200..06871eb53 100644
--- a/src/redist/targets/GenerateBundledVersions.targets
+++ b/src/redist/targets/GenerateBundledVersions.targets
@@ -1195,9 +1195,13 @@ Copyright (c) .NET Foundation. All rights reserved.
           DestinationFiles="$(SdkOutputDirectory)RuntimeIdentifierGraph.json"
           SkipUnchangedFiles="true"/>
 
+    <Copy SourceFiles="$(NuGetPackageRoot)/microsoft.netcore.platforms/$(_NETCorePlatformsPackageVersion)/PortableRuntimeIdentifierGraph.json"
+          DestinationFolder="$(SdkOutputDirectory)"
+          SkipUnchangedFiles="true"/>
+
     <GenerateSdkRuntimeIdentifierChain
           RuntimeIdentifier="$(PortableProductMonikerRid)"
-          RuntimeIdentifierGraphPath="$(SdkOutputDirectory)RuntimeIdentifierGraph.json"
+          RuntimeIdentifierGraphPath="$(SdkOutputDirectory)PortableRuntimeIdentifierGraph.json"
           RuntimeIdentifierChainOutputPath="$(SdkOutputDirectory)NETCoreSdkRuntimeIdentifierChain.txt"/>
 
   </Target>