diff --git a/src/libraries/NetCoreAppLibrary.props b/src/libraries/NetCoreAppLibrary.props
index 5c46266cb56e73..66e816eed49f71 100644
--- a/src/libraries/NetCoreAppLibrary.props
+++ b/src/libraries/NetCoreAppLibrary.props
@@ -60,6 +60,7 @@
       System.Drawing.Primitives;
       System.Dynamic.Runtime;
       System.Formats.Asn1;
+      System.Formats.Tar;
       System.Globalization;
       System.Globalization.Calendars;
       System.Globalization.Extensions;
diff --git a/src/libraries/System.Formats.Tar/src/System.Formats.Tar.csproj b/src/libraries/System.Formats.Tar/src/System.Formats.Tar.csproj
index 928dca2b22fd0f..2cef71d5e33dfc 100644
--- a/src/libraries/System.Formats.Tar/src/System.Formats.Tar.csproj
+++ b/src/libraries/System.Formats.Tar/src/System.Formats.Tar.csproj
@@ -1,19 +1,17 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-    <TargetFrameworks>$(NetCoreAppCurrent)-windows;$(NetCoreAppCurrent)-Unix</TargetFrameworks>
+    <TargetFrameworks>$(NetCoreAppCurrent)-windows;$(NetCoreAppCurrent)-Unix;$(NetCoreAppCurrent)</TargetFrameworks>
     <Nullable>enable</Nullable>
-    <PackageDescription>
-      Provides classes that can read and write the Tar archive format.
+  </PropertyGroup>
 
-      Commonly Used Types:
-      System.Formats.Tar.TarFile
-      System.Formats.Tar.TarEntry
-      System.Formats.Tar.TarReader
-      System.Formats.Tar.TarWriter
-    </PackageDescription>
+  <!-- DesignTimeBuild requires all the TargetFramework Derived Properties to not be present in the first property group. -->
+  <PropertyGroup>
+    <TargetPlatformIdentifier>$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)'))</TargetPlatformIdentifier>
+    <GeneratePlatformNotSupportedAssemblyMessage Condition="'$(TargetPlatformIdentifier)' == ''">SR.PlatformNotSupported_SystemFormatsTar</GeneratePlatformNotSupportedAssemblyMessage>
   </PropertyGroup>
-  <ItemGroup>
+
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != ''">
     <Compile Include="System\Formats\Tar\FieldLengths.cs" />
     <Compile Include="System\Formats\Tar\FieldLocations.cs" />
     <Compile Include="System\Formats\Tar\PosixTarEntry.cs" />
@@ -52,7 +50,7 @@
     <Compile Include="$(CommonPath)System\Text\ValueStringBuilder.cs" Link="Common\System\Text\ValueStringBuilder.cs" />
   </ItemGroup>
   <!-- Unix specific files -->
-  <ItemGroup Condition="'$(TargetPlatformIdentifier)' != 'windows'">
+  <ItemGroup Condition="'$(TargetPlatformIdentifier)' == 'Unix'">
     <Compile Include="System\Formats\Tar\TarEntry.Unix.cs" />
     <Compile Include="System\Formats\Tar\TarWriter.Unix.cs" />
     <Compile Include="$(CommonPath)Interop\Unix\Interop.IOErrors.cs" Link="Common\Interop\Unix\Interop.IOErrors.cs" />
@@ -70,8 +68,6 @@
     <Reference Include="System.Collections" />
     <Reference Include="System.Memory" />
     <Reference Include="System.Runtime" />
-    <Reference Include="System.Runtime.CompilerServices.Unsafe" />
-    <Reference Include="System.Runtime.Extensions" />
     <Reference Include="System.Runtime.InteropServices" />
     <Reference Include="System.Threading" />
   </ItemGroup>