diff --git a/src/Installer/core-sdk-tasks/Enumerations/BuildPlatform.cs b/src/Installer/core-sdk-tasks/Enumerations/BuildPlatform.cs
deleted file mode 100644
index 72e68a0dc200..000000000000
--- a/src/Installer/core-sdk-tasks/Enumerations/BuildPlatform.cs
+++ /dev/null
@@ -1,20 +0,0 @@
-// Copyright (c) .NET Foundation and contributors. All rights reserved.
-// Licensed under the MIT license. See LICENSE file in the project root for full license information.
-
-namespace Microsoft.DotNet.Cli.Build.Framework
-{
-    public enum BuildPlatform
-    {
-        Windows = 1,
-        Unix = 2,
-        Linux = 3,
-        OSX = 4,
-        Ubuntu = 5,
-        CentOS = 6,
-        RHEL = 7,
-        Debian = 8,
-        Fedora = 9,
-        OpenSuse = 10,
-        FreeBSD = 11
-    }
-}
diff --git a/src/Installer/redist-installer/targets/GetRuntimeInformation.targets b/src/Installer/redist-installer/targets/GetRuntimeInformation.targets
index e05828c83ea9..db1510b166c0 100644
--- a/src/Installer/redist-installer/targets/GetRuntimeInformation.targets
+++ b/src/Installer/redist-installer/targets/GetRuntimeInformation.targets
@@ -11,6 +11,7 @@
       <HostOSName Condition=" '$(HostOSName)' == '' AND $([MSBuild]::IsOSPlatform('WINDOWS')) ">win</HostOSName>
       <HostOSName Condition=" '$(HostOSName)' == '' AND $([MSBuild]::IsOSPlatform('OSX')) ">osx</HostOSName>
       <HostOSName Condition=" '$(HostOSName)' == '' AND $([MSBuild]::IsOSPlatform('FREEBSD')) ">freebsd</HostOSName>
+      <HostOSName Condition=" '$(HostOSName)' == '' AND $([MSBuild]::IsOSPlatform('ILLUMOS')) ">illumos</HostOSName>
       <HostOSName Condition=" '$(HostOSName)' == '' AND '$(IsLinux)' == 'True' ">linux</HostOSName>
 
       <OSName Condition=" '$(OSName)' == '' AND $(Rid) != '' ">$(Rid.Substring(0, $(Rid.LastIndexOf('-'))))</OSName>
diff --git a/src/Installer/redist-installer/targets/SetBuildDefaults.targets b/src/Installer/redist-installer/targets/SetBuildDefaults.targets
index 5e6a4bd729b1..e77c7d15b4b6 100644
--- a/src/Installer/redist-installer/targets/SetBuildDefaults.targets
+++ b/src/Installer/redist-installer/targets/SetBuildDefaults.targets
@@ -7,6 +7,7 @@
       <SkipBuildingInstallers Condition=" '$(SkipBuildingInstallers)' == '' AND
         ($(Rid.StartsWith('rhel.6'))
         OR $(Rid.StartsWith('freebsd'))
+        OR $(Rid.StartsWith('illumos'))
         OR $(Rid.StartsWith('linux-musl'))
         OR $(Rid.StartsWith('ubuntu.18.04')))">true</SkipBuildingInstallers>
       <SkipBuildingInstallers Condition=" '$(SkipBuildingInstallers)' == '' ">false</SkipBuildingInstallers>
diff --git a/src/Layout/toolset-tasks/Enumerations/BuildPlatform.cs b/src/Layout/toolset-tasks/Enumerations/BuildPlatform.cs
deleted file mode 100644
index 041bc0216b48..000000000000
--- a/src/Layout/toolset-tasks/Enumerations/BuildPlatform.cs
+++ /dev/null
@@ -1,20 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-namespace Microsoft.DotNet.Cli.Build.Framework
-{
-    public enum BuildPlatform
-    {
-        Windows = 1,
-        Unix = 2,
-        Linux = 3,
-        OSX = 4,
-        Ubuntu = 5,
-        CentOS = 6,
-        RHEL = 7,
-        Debian = 8,
-        Fedora = 9,
-        OpenSuse = 10,
-        FreeBSD = 11
-    }
-}
diff --git a/src/Tasks/Microsoft.NET.Build.Tasks/GenerateBundle.cs b/src/Tasks/Microsoft.NET.Build.Tasks/GenerateBundle.cs
index 047ef4d25b61..9aff7c5bc8b2 100644
--- a/src/Tasks/Microsoft.NET.Build.Tasks/GenerateBundle.cs
+++ b/src/Tasks/Microsoft.NET.Build.Tasks/GenerateBundle.cs
@@ -35,7 +35,10 @@ public class GenerateBundle : TaskBase
         protected override void ExecuteCore()
         {
             OSPlatform targetOS = RuntimeIdentifier.StartsWith("win") ? OSPlatform.Windows :
-                                  RuntimeIdentifier.StartsWith("osx") ? OSPlatform.OSX : OSPlatform.Linux;
+                                  RuntimeIdentifier.StartsWith("osx") ? OSPlatform.OSX :
+                                  RuntimeIdentifier.StartsWith("freebsd") ? OSPlatform.Create("FREEBSD") :
+                                  RuntimeIdentifier.StartsWith("illumos") ? OSPlatform.Create("ILLUMOS") :
+                                  OSPlatform.Linux;
 
             Architecture targetArch = RuntimeIdentifier.EndsWith("-x64") || RuntimeIdentifier.Contains("-x64-") ? Architecture.X64 :
                                       RuntimeIdentifier.EndsWith("-x86") || RuntimeIdentifier.Contains("-x86-") ? Architecture.X86 :
diff --git a/src/Tasks/Microsoft.NET.Build.Tasks/ResolveReadyToRunCompilers.cs b/src/Tasks/Microsoft.NET.Build.Tasks/ResolveReadyToRunCompilers.cs
index f14d4a4cf6ee..63c12a3a749c 100644
--- a/src/Tasks/Microsoft.NET.Build.Tasks/ResolveReadyToRunCompilers.cs
+++ b/src/Tasks/Microsoft.NET.Build.Tasks/ResolveReadyToRunCompilers.cs
@@ -185,7 +185,7 @@ private bool GetCrossgen2TargetOS(out string targetOS)
             string portablePlatform = NuGetUtils.GetBestMatchingRid(
                     runtimeGraph,
                     _targetPlatform,
-                    new[] { "linux", "linux-musl", "osx", "win", "freebsd" },
+                    new[] { "linux", "linux-musl", "osx", "win", "freebsd", "illumos" },
                     out _);
 
             // For source-build, allow the bootstrap SDK rid to be unknown to the runtime repo graph.
@@ -199,6 +199,14 @@ private bool GetCrossgen2TargetOS(out string targetOS)
                 {
                     portablePlatform = "linux";
                 }
+                else if (RuntimeInformation.IsOSPlatform(OSPlatform.Create("FREEBSD")))
+                {
+                    portablePlatform = "freebsd";
+                }
+                else if (RuntimeInformation.IsOSPlatform(OSPlatform.Create("ILLUMOS")))
+                {
+                    portablePlatform = "illumos";
+                }
                 else if (RuntimeInformation.IsOSPlatform(OSPlatform.OSX))
                 {
                     portablePlatform = "osx";
@@ -212,6 +220,7 @@ private bool GetCrossgen2TargetOS(out string targetOS)
                 "osx" => "osx",
                 "win" => "windows",
                 "freebsd" => "freebsd",
+                "illumos" => "illumos",
                 _ => null
             };