diff --git a/src/coreclr/System.Private.CoreLib/System.Private.CoreLib.csproj b/src/coreclr/System.Private.CoreLib/System.Private.CoreLib.csproj
index 9ef1024c449da8..fdd395fe520a01 100644
--- a/src/coreclr/System.Private.CoreLib/System.Private.CoreLib.csproj
+++ b/src/coreclr/System.Private.CoreLib/System.Private.CoreLib.csproj
@@ -39,6 +39,7 @@
   <PropertyGroup>
     <Platform Condition=" '$(Platform)' == '' ">$(TargetArchitecture)</Platform>
     <Platform Condition=" '$(Platform)' == 'armel' ">arm</Platform>
+    <PlatformTarget>AnyCPU</PlatformTarget>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <!-- This prevents the default MsBuild targets from referencing System.Core.dll -->
     <AddAdditionalExplicitAssemblyReferences>false</AddAdditionalExplicitAssemblyReferences>
@@ -59,28 +60,21 @@
 
   <!-- Platform specific properties -->
   <PropertyGroup Condition="'$(Platform)' == 'x64'">
-    <PlatformTarget>x64</PlatformTarget>
-    <Prefer32Bit>false</Prefer32Bit>
     <DefineConstants>$(DefineConstants);TARGET_AMD64</DefineConstants>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Platform)' == 'x86'">
-    <PlatformTarget>x86</PlatformTarget>
     <DefineConstants>$(DefineConstants);TARGET_X86</DefineConstants>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Platform)' == 'arm'">
-    <PlatformTarget>arm</PlatformTarget>
     <DefineConstants>$(DefineConstants);TARGET_ARM</DefineConstants>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Platform)' == 'arm64'">
-    <PlatformTarget>AnyCPU</PlatformTarget>
     <DefineConstants>$(DefineConstants);TARGET_ARM64</DefineConstants>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Platform)' == 'loongarch64'">
-    <PlatformTarget>AnyCPU</PlatformTarget>
     <DefineConstants>$(DefineConstants);TARGET_LOONGARCH64</DefineConstants>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Platform)' == 'riscv64'">
-    <PlatformTarget>AnyCPU</PlatformTarget>
     <DefineConstants>$(DefineConstants);TARGET_RISCV64</DefineConstants>
   </PropertyGroup>
 
diff --git a/src/coreclr/nativeaot/Directory.Build.props b/src/coreclr/nativeaot/Directory.Build.props
index 42e6f968e0e1e9..d3277aa58ece73 100644
--- a/src/coreclr/nativeaot/Directory.Build.props
+++ b/src/coreclr/nativeaot/Directory.Build.props
@@ -21,6 +21,7 @@
 
     <Platform Condition=" '$(Platform)' == '' ">$(TargetArchitecture)</Platform>
     <Platform Condition=" '$(Platform)' == 'armel' ">arm</Platform>
+    <PlatformTarget>AnyCPU</PlatformTarget>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <!-- This prevents the default MsBuild targets from referencing System.Core.dll -->
     <AddAdditionalExplicitAssemblyReferences>false</AddAdditionalExplicitAssemblyReferences>
@@ -78,20 +79,15 @@
 
   <!-- Platform specific properties -->
   <PropertyGroup Condition="'$(Platform)' == 'x64'">
-    <PlatformTarget>x64</PlatformTarget>
-    <Prefer32Bit>false</Prefer32Bit>
     <DefineConstants>TARGET_64BIT;TARGET_AMD64;$(DefineConstants)</DefineConstants>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Platform)' == 'x86'">
-    <PlatformTarget>x86</PlatformTarget>
     <DefineConstants>TARGET_32BIT;TARGET_X86;$(DefineConstants)</DefineConstants>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Platform)' == 'arm'">
-    <PlatformTarget>arm</PlatformTarget>
     <DefineConstants>TARGET_32BIT;TARGET_ARM;$(DefineConstants)</DefineConstants>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Platform)' == 'arm64'">
-    <PlatformTarget>AnyCPU</PlatformTarget>
     <DefineConstants>TARGET_64BIT;TARGET_ARM64;$(DefineConstants)</DefineConstants>
   </PropertyGroup>
 
diff --git a/src/mono/System.Private.CoreLib/System.Private.CoreLib.csproj b/src/mono/System.Private.CoreLib/System.Private.CoreLib.csproj
index 95f7f110cda509..905dc83eb08dee 100644
--- a/src/mono/System.Private.CoreLib/System.Private.CoreLib.csproj
+++ b/src/mono/System.Private.CoreLib/System.Private.CoreLib.csproj
@@ -26,6 +26,7 @@
   </ItemGroup>
 
   <PropertyGroup>
+    <PlatformTarget>AnyCPU</PlatformTarget>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <!-- This prevents the default MsBuild targets from referencing System.Core.dll -->
     <AddAdditionalExplicitAssemblyReferences>false</AddAdditionalExplicitAssemblyReferences>
@@ -48,40 +49,30 @@
 
   <!-- Platform specific properties -->
   <PropertyGroup Condition="'$(Platform)' == 'x64'">
-    <PlatformTarget>x64</PlatformTarget>
-    <Prefer32Bit>false</Prefer32Bit>
     <DefineConstants>$(DefineConstants);TARGET_AMD64</DefineConstants>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Platform)' == 'x86'">
-    <PlatformTarget>x86</PlatformTarget>
     <DefineConstants>$(DefineConstants);TARGET_X86</DefineConstants>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Platform)' == 'armv6'">
-    <PlatformTarget>arm</PlatformTarget>
     <DefineConstants>$(DefineConstants);TARGET_ARMV6</DefineConstants>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Platform)' == 'arm'">
-    <PlatformTarget>arm</PlatformTarget>
     <DefineConstants>$(DefineConstants);TARGET_ARM</DefineConstants>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Platform)' == 'arm64'">
-    <PlatformTarget>AnyCPU</PlatformTarget>
     <DefineConstants>$(DefineConstants);TARGET_ARM64</DefineConstants>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Platform)' == 'riscv64'">
-    <PlatformTarget>AnyCPU</PlatformTarget>
     <DefineConstants>$(DefineConstants);TARGET_RISCV64</DefineConstants>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Platform)' == 's390x'">
-    <PlatformTarget>AnyCPU</PlatformTarget>
     <DefineConstants>$(DefineConstants);TARGET_S390X</DefineConstants>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Platform)' == 'wasm'">
-    <PlatformTarget>AnyCPU</PlatformTarget>
     <DefineConstants>$(DefineConstants);TARGET_WASM</DefineConstants>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Platform)' == 'ppc64le'">
-    <PlatformTarget>AnyCPU</PlatformTarget>
     <DefineConstants>$(DefineConstants);TARGET_POWERPC64</DefineConstants>
   </PropertyGroup>