diff --git a/.gitignore b/.gitignore
index fd02261e5f..5af949b050 100644
--- a/.gitignore
+++ b/.gitignore
@@ -28,4 +28,5 @@ project.lock.json
 .vs
 .build/
 .testPublish/
-samples/**/temp-keys/
\ No newline at end of file
+samples/**/temp-keys/
+global.json
diff --git a/samples/CustomEncryptorSample/CustomEncryptorSample.csproj b/samples/CustomEncryptorSample/CustomEncryptorSample.csproj
index 7422388415..96ea1517fa 100644
--- a/samples/CustomEncryptorSample/CustomEncryptorSample.csproj
+++ b/samples/CustomEncryptorSample/CustomEncryptorSample.csproj
@@ -3,7 +3,7 @@
   <Import Project="..\..\build\dependencies.props" />
 
   <PropertyGroup>
-    <TargetFrameworks>net451;netcoreapp2.0</TargetFrameworks>
+    <TargetFrameworks>net46;netcoreapp2.0</TargetFrameworks>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/samples/KeyManagementSample/KeyManagementSample.csproj b/samples/KeyManagementSample/KeyManagementSample.csproj
index 1b23de0ddf..dd0a98bd0c 100644
--- a/samples/KeyManagementSample/KeyManagementSample.csproj
+++ b/samples/KeyManagementSample/KeyManagementSample.csproj
@@ -3,7 +3,7 @@
   <Import Project="..\..\build\dependencies.props" />
 
   <PropertyGroup>
-    <TargetFrameworks>net451;netcoreapp2.0</TargetFrameworks>
+    <TargetFrameworks>net46;netcoreapp2.0</TargetFrameworks>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/samples/NonDISample/NonDISample.csproj b/samples/NonDISample/NonDISample.csproj
index 1b23de0ddf..dd0a98bd0c 100644
--- a/samples/NonDISample/NonDISample.csproj
+++ b/samples/NonDISample/NonDISample.csproj
@@ -3,7 +3,7 @@
   <Import Project="..\..\build\dependencies.props" />
 
   <PropertyGroup>
-    <TargetFrameworks>net451;netcoreapp2.0</TargetFrameworks>
+    <TargetFrameworks>net46;netcoreapp2.0</TargetFrameworks>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/samples/Redis/Redis.csproj b/samples/Redis/Redis.csproj
index 73863155a2..6952eb460c 100644
--- a/samples/Redis/Redis.csproj
+++ b/samples/Redis/Redis.csproj
@@ -3,7 +3,7 @@
   <Import Project="..\..\build\dependencies.props" />
 
   <PropertyGroup>
-    <TargetFrameworks>netcoreapp2.0;net451</TargetFrameworks>
+    <TargetFrameworks>netcoreapp2.0;net46</TargetFrameworks>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/src/Microsoft.AspNetCore.Cryptography.Internal/CryptoUtil.cs b/src/Microsoft.AspNetCore.Cryptography.Internal/CryptoUtil.cs
index 8a268af986..45f405248d 100644
--- a/src/Microsoft.AspNetCore.Cryptography.Internal/CryptoUtil.cs
+++ b/src/Microsoft.AspNetCore.Cryptography.Internal/CryptoUtil.cs
@@ -73,8 +73,11 @@ namespace Microsoft.AspNetCore.Cryptography
         }
 
         [MethodImpl(MethodImplOptions.NoInlining | MethodImplOptions.NoOptimization)]
-#if !NETSTANDARD1_3
+#if NET46
         [ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)]
+#elif NETSTANDARD1_3
+#else
+#error target frameworks need to be updated.
 #endif
         public static bool TimeConstantBuffersAreEqual(byte* bufA, byte* bufB, uint count)
         {
diff --git a/src/Microsoft.AspNetCore.Cryptography.Internal/Microsoft.AspNetCore.Cryptography.Internal.csproj b/src/Microsoft.AspNetCore.Cryptography.Internal/Microsoft.AspNetCore.Cryptography.Internal.csproj
index 75e58c0965..ee4be7ad30 100644
--- a/src/Microsoft.AspNetCore.Cryptography.Internal/Microsoft.AspNetCore.Cryptography.Internal.csproj
+++ b/src/Microsoft.AspNetCore.Cryptography.Internal/Microsoft.AspNetCore.Cryptography.Internal.csproj
@@ -4,7 +4,7 @@
 
   <PropertyGroup>
     <Description>Infrastructure for ASP.NET Core cryptographic packages. Applications and libraries should not reference this package directly.</Description>
-    <TargetFrameworks>net451;netstandard1.3</TargetFrameworks>
+    <TargetFrameworks>net46;netstandard1.3</TargetFrameworks>
     <NoWarn>$(NoWarn);CS1591</NoWarn>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
diff --git a/src/Microsoft.AspNetCore.Cryptography.Internal/SafeHandles/SafeHandleZeroOrMinusOneIsInvalid.cs b/src/Microsoft.AspNetCore.Cryptography.Internal/SafeHandles/SafeHandleZeroOrMinusOneIsInvalid.cs
index 2c7ca7eb33..b61a4c3c44 100644
--- a/src/Microsoft.AspNetCore.Cryptography.Internal/SafeHandles/SafeHandleZeroOrMinusOneIsInvalid.cs
+++ b/src/Microsoft.AspNetCore.Cryptography.Internal/SafeHandles/SafeHandleZeroOrMinusOneIsInvalid.cs
@@ -24,4 +24,7 @@ namespace Microsoft.Win32.SafeHandles
         }
     }
 }
+#elif NET46
+#else
+#error target frameworks need to be updated.
 #endif
diff --git a/src/Microsoft.AspNetCore.Cryptography.Internal/SafeHandles/SafeLibraryHandle.cs b/src/Microsoft.AspNetCore.Cryptography.Internal/SafeHandles/SafeLibraryHandle.cs
index c6ed16428b..c1ee52202e 100644
--- a/src/Microsoft.AspNetCore.Cryptography.Internal/SafeHandles/SafeLibraryHandle.cs
+++ b/src/Microsoft.AspNetCore.Cryptography.Internal/SafeHandles/SafeLibraryHandle.cs
@@ -127,23 +127,30 @@ namespace Microsoft.AspNetCore.Cryptography.SafeHandles
             return UnsafeNativeMethods.FreeLibrary(handle);
         }
 
-#if !NETSTANDARD1_3
+#if NET46
         [SuppressUnmanagedCodeSecurity]
+#elif NETSTANDARD1_3
+#else
+#error target frameworks need to be updated.
 #endif
         private static class UnsafeNativeMethods
         {
 #if NETSTANDARD1_3
             private const string CORE_LIBRARY_LOADER_LIB = "api-ms-win-core-libraryloader-l1-1-0.dll";
             private const string CORE_LOCALIZATION_LIB = "api-ms-win-core-localization-l1-2-0.dll";
-#else
+#elif NET46
             private const string KERNEL32_LIB = "kernel32.dll";
+#else
+#error target frameworks need to be updated.
 #endif
 
             // http://msdn.microsoft.com/en-us/library/windows/desktop/ms679351(v=vs.85).aspx
 #if NETSTANDARD1_3
             [DllImport(CORE_LOCALIZATION_LIB, EntryPoint = "FormatMessageW", CallingConvention = CallingConvention.Winapi, CharSet = CharSet.Unicode, SetLastError = true)]
-#else
+#elif NET46
             [DllImport(KERNEL32_LIB, EntryPoint = "FormatMessageW", CallingConvention = CallingConvention.Winapi, CharSet = CharSet.Unicode, SetLastError = true)]
+#else
+#error target frameworks need to be updated.
 #endif
             public static extern int FormatMessage(
                 [In] uint dwFlags,
@@ -159,9 +166,11 @@ namespace Microsoft.AspNetCore.Cryptography.SafeHandles
             [return: MarshalAs(UnmanagedType.Bool)]
 #if NETSTANDARD1_3
             [DllImport(CORE_LIBRARY_LOADER_LIB, CallingConvention = CallingConvention.Winapi, CharSet = CharSet.Unicode)]
-#else
+#elif NET46
             [ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)]
             [DllImport(KERNEL32_LIB, CallingConvention = CallingConvention.Winapi, CharSet = CharSet.Unicode)]
+#else
+#error target frameworks need to be updated.
 #endif
             internal static extern bool FreeLibrary(IntPtr hModule);
 
@@ -169,8 +178,10 @@ namespace Microsoft.AspNetCore.Cryptography.SafeHandles
             [return: MarshalAs(UnmanagedType.Bool)]
 #if NETSTANDARD1_3
             [DllImport(CORE_LIBRARY_LOADER_LIB, EntryPoint = "GetModuleHandleExW", CallingConvention = CallingConvention.Winapi, SetLastError = true)]
-#else
+#elif NET46
             [DllImport(KERNEL32_LIB, EntryPoint = "GetModuleHandleExW", CallingConvention = CallingConvention.Winapi, SetLastError = true)]
+#else
+#error target frameworks need to be updated.
 #endif
             internal static extern bool GetModuleHandleEx(
                 [In] uint dwFlags,
@@ -180,8 +191,10 @@ namespace Microsoft.AspNetCore.Cryptography.SafeHandles
             // http://msdn.microsoft.com/en-us/library/ms683212(v=vs.85).aspx
 #if NETSTANDARD1_3
             [DllImport(CORE_LIBRARY_LOADER_LIB, CallingConvention = CallingConvention.Winapi, SetLastError = true)]
-#else
+#elif NET46
             [DllImport(KERNEL32_LIB, CallingConvention = CallingConvention.Winapi, SetLastError = true)]
+#else
+#error target frameworks need to be updated.
 #endif
             internal static extern IntPtr GetProcAddress(
                 [In] SafeLibraryHandle hModule,
@@ -190,8 +203,10 @@ namespace Microsoft.AspNetCore.Cryptography.SafeHandles
             // http://msdn.microsoft.com/en-us/library/windows/desktop/ms684179(v=vs.85).aspx
 #if NETSTANDARD1_3
             [DllImport(CORE_LIBRARY_LOADER_LIB, EntryPoint = "LoadLibraryExW", CallingConvention = CallingConvention.Winapi, SetLastError = true)]
-#else
+#elif NET46
             [DllImport(KERNEL32_LIB, EntryPoint = "LoadLibraryExW", CallingConvention = CallingConvention.Winapi, SetLastError = true)]
+#else
+#error target frameworks need to be updated.
 #endif
             internal static extern SafeLibraryHandle LoadLibraryEx(
                 [In, MarshalAs(UnmanagedType.LPWStr)] string lpFileName,
diff --git a/src/Microsoft.AspNetCore.Cryptography.Internal/SafeHandles/SecureLocalAllocHandle.cs b/src/Microsoft.AspNetCore.Cryptography.Internal/SafeHandles/SecureLocalAllocHandle.cs
index 9c7faeed90..52399e0f7b 100644
--- a/src/Microsoft.AspNetCore.Cryptography.Internal/SafeHandles/SecureLocalAllocHandle.cs
+++ b/src/Microsoft.AspNetCore.Cryptography.Internal/SafeHandles/SecureLocalAllocHandle.cs
@@ -41,8 +41,11 @@ namespace Microsoft.AspNetCore.Cryptography.SafeHandles
             return newHandle;
         }
 
-#if !NETSTANDARD1_3
+#if NET46
         [ReliabilityContract(Consistency.WillNotCorruptState, Cer.MayFail)]
+#elif NETSTANDARD1_3
+#else
+#error target frameworks need to be updated.
 #endif
         private void AllocateImpl(IntPtr cb)
         {
diff --git a/src/Microsoft.AspNetCore.Cryptography.Internal/UnsafeNativeMethods.cs b/src/Microsoft.AspNetCore.Cryptography.Internal/UnsafeNativeMethods.cs
index 73cf4e91bd..c36f78997b 100644
--- a/src/Microsoft.AspNetCore.Cryptography.Internal/UnsafeNativeMethods.cs
+++ b/src/Microsoft.AspNetCore.Cryptography.Internal/UnsafeNativeMethods.cs
@@ -12,14 +12,17 @@ using Microsoft.AspNetCore.Cryptography.Cng;
 using Microsoft.AspNetCore.Cryptography.SafeHandles;
 using Microsoft.Win32.SafeHandles;
 
-#if !NETSTANDARD1_3
+#if NET46
 using System.Runtime.ConstrainedExecution;
 #endif
 
 namespace Microsoft.AspNetCore.Cryptography
 {
-#if !NETSTANDARD1_3
+#if NET46
     [SuppressUnmanagedCodeSecurity]
+#elif NETSTANDARD1_3
+#else
+#error target frameworks need to be updated.
 #endif
     internal unsafe static class UnsafeNativeMethods
     {
@@ -87,16 +90,22 @@ namespace Microsoft.AspNetCore.Cryptography
             [In] uint dwFlags);
 
         [DllImport(BCRYPT_LIB, CallingConvention = CallingConvention.Winapi)]
-#if !NETSTANDARD1_3
+#if NET46
         [ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)]
+#elif NETSTANDARD1_3
+#else
+#error target frameworks need to be updated.
 #endif
         // http://msdn.microsoft.com/en-us/library/windows/desktop/aa375399(v=vs.85).aspx
         internal static extern int BCryptDestroyHash(
             [In] IntPtr hHash);
 
         [DllImport(BCRYPT_LIB, CallingConvention = CallingConvention.Winapi)]
-#if !NETSTANDARD1_3
+#if NET46
         [ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)]
+#elif NETSTANDARD1_3
+#else
+#error target frameworks need to be updated.
 #endif
         // http://msdn.microsoft.com/en-us/library/windows/desktop/aa375404(v=vs.85).aspx
         internal static extern int BCryptDestroyKey(
@@ -249,8 +258,11 @@ namespace Microsoft.AspNetCore.Cryptography
          */
 
         [DllImport(NCRYPT_LIB, CallingConvention = CallingConvention.Winapi)]
-#if !NETSTANDARD1_3
+#if NET46
         [ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)]
+#elif NETSTANDARD1_3
+#else
+#error target frameworks need to be updated.
 #endif
         // http://msdn.microsoft.com/en-us/library/windows/desktop/hh706799(v=vs.85).aspx
         internal static extern int NCryptCloseProtectionDescriptor(
diff --git a/src/Microsoft.AspNetCore.Cryptography.KeyDerivation/Microsoft.AspNetCore.Cryptography.KeyDerivation.csproj b/src/Microsoft.AspNetCore.Cryptography.KeyDerivation/Microsoft.AspNetCore.Cryptography.KeyDerivation.csproj
index a93ee65f94..4ff88fbf5e 100644
--- a/src/Microsoft.AspNetCore.Cryptography.KeyDerivation/Microsoft.AspNetCore.Cryptography.KeyDerivation.csproj
+++ b/src/Microsoft.AspNetCore.Cryptography.KeyDerivation/Microsoft.AspNetCore.Cryptography.KeyDerivation.csproj
@@ -4,7 +4,7 @@
 
   <PropertyGroup>
     <Description>ASP.NET Core utilities for key derivation.</Description>
-    <TargetFrameworks>net451;netstandard1.3</TargetFrameworks>
+    <TargetFramework>netstandard1.3</TargetFramework>
     <NoWarn>$(NoWarn);CS1591</NoWarn>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
diff --git a/src/Microsoft.AspNetCore.DataProtection.Abstractions/Microsoft.AspNetCore.DataProtection.Abstractions.csproj b/src/Microsoft.AspNetCore.DataProtection.Abstractions/Microsoft.AspNetCore.DataProtection.Abstractions.csproj
index 4a2cef6f08..788a8fc77c 100644
--- a/src/Microsoft.AspNetCore.DataProtection.Abstractions/Microsoft.AspNetCore.DataProtection.Abstractions.csproj
+++ b/src/Microsoft.AspNetCore.DataProtection.Abstractions/Microsoft.AspNetCore.DataProtection.Abstractions.csproj
@@ -7,7 +7,7 @@
 Commonly used types:
 Microsoft.AspNetCore.DataProtection.IDataProtectionProvider
 Microsoft.AspNetCore.DataProtection.IDataProtector</Description>
-    <TargetFrameworks>net451;netstandard1.3</TargetFrameworks>
+    <TargetFramework>netstandard1.3</TargetFramework>
     <NoWarn>$(NoWarn);CS1591</NoWarn>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <PackageTags>aspnetcore;dataprotection</PackageTags>
diff --git a/src/Microsoft.AspNetCore.DataProtection.AzureStorage/Microsoft.AspNetCore.DataProtection.AzureStorage.csproj b/src/Microsoft.AspNetCore.DataProtection.AzureStorage/Microsoft.AspNetCore.DataProtection.AzureStorage.csproj
index b830b0f744..c2c890d657 100644
--- a/src/Microsoft.AspNetCore.DataProtection.AzureStorage/Microsoft.AspNetCore.DataProtection.AzureStorage.csproj
+++ b/src/Microsoft.AspNetCore.DataProtection.AzureStorage/Microsoft.AspNetCore.DataProtection.AzureStorage.csproj
@@ -5,7 +5,7 @@
   <PropertyGroup>
     <Description>Microsoft Azure Blob storrage support as key store.</Description>
     <VersionPrefix>1.1.0</VersionPrefix>
-    <TargetFrameworks>net451;netstandard1.5</TargetFrameworks>
+    <TargetFrameworks>net46;netstandard1.5</TargetFrameworks>
     <NoWarn>$(NoWarn);CS1591</NoWarn>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
diff --git a/src/Microsoft.AspNetCore.DataProtection.Extensions/DataProtectionProvider.cs b/src/Microsoft.AspNetCore.DataProtection.Extensions/DataProtectionProvider.cs
index 58972aa4d9..1b9e30a94e 100644
--- a/src/Microsoft.AspNetCore.DataProtection.Extensions/DataProtectionProvider.cs
+++ b/src/Microsoft.AspNetCore.DataProtection.Extensions/DataProtectionProvider.cs
@@ -73,7 +73,7 @@ namespace Microsoft.AspNetCore.DataProtection
             return CreateProvider(keyDirectory, setupAction, certificate: null);
         }
 
-#if !NETSTANDARD1_3 // [[ISSUE60]] Remove this #ifdef when Core CLR gets support for EncryptedXml
+#if NET46 // [[ISSUE60]] Remove this #ifdef when Core CLR gets support for EncryptedXml
         /// <summary>
         /// Creates a <see cref="DataProtectionProvider"/> that store keys in a location based on
         /// the platform and operating system and uses the given <see cref="X509Certificate2"/> to encrypt the keys.
@@ -150,6 +150,9 @@ namespace Microsoft.AspNetCore.DataProtection
 
             return CreateProvider(keyDirectory, setupAction, certificate);
         }
+#elif NETSTANDARD1_3
+#else
+#error target frameworks need to be updated.
 #endif
 
         private static IDataProtectionProvider CreateProvider(
@@ -166,11 +169,14 @@ namespace Microsoft.AspNetCore.DataProtection
                 builder.PersistKeysToFileSystem(keyDirectory);
             }
 
-#if !NETSTANDARD1_3 // [[ISSUE60]] Remove this #ifdef when Core CLR gets support for EncryptedXml
+#if NET46 // [[ISSUE60]] Remove this #ifdef when Core CLR gets support for EncryptedXml
             if (certificate != null)
             {
                 builder.ProtectKeysWithCertificate(certificate);
             }
+#elif NETSTANDARD1_3
+#else
+#error target frameworks need to be updated.
 #endif
 
             setupAction(builder);
diff --git a/src/Microsoft.AspNetCore.DataProtection.Extensions/Microsoft.AspNetCore.DataProtection.Extensions.csproj b/src/Microsoft.AspNetCore.DataProtection.Extensions/Microsoft.AspNetCore.DataProtection.Extensions.csproj
index 41950e5567..fe2f163044 100644
--- a/src/Microsoft.AspNetCore.DataProtection.Extensions/Microsoft.AspNetCore.DataProtection.Extensions.csproj
+++ b/src/Microsoft.AspNetCore.DataProtection.Extensions/Microsoft.AspNetCore.DataProtection.Extensions.csproj
@@ -4,7 +4,7 @@
 
   <PropertyGroup>
     <Description>Additional APIs for ASP.NET Core data protection.</Description>
-    <TargetFrameworks>net451;netstandard1.3</TargetFrameworks>
+    <TargetFrameworks>net46;netstandard1.3</TargetFrameworks>
     <NoWarn>$(NoWarn);CS1591</NoWarn>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <PackageTags>aspnetcore;dataprotection</PackageTags>
diff --git a/src/Microsoft.AspNetCore.DataProtection.Redis/Microsoft.AspNetCore.DataProtection.Redis.csproj b/src/Microsoft.AspNetCore.DataProtection.Redis/Microsoft.AspNetCore.DataProtection.Redis.csproj
index de1593b27f..e305facf8d 100644
--- a/src/Microsoft.AspNetCore.DataProtection.Redis/Microsoft.AspNetCore.DataProtection.Redis.csproj
+++ b/src/Microsoft.AspNetCore.DataProtection.Redis/Microsoft.AspNetCore.DataProtection.Redis.csproj
@@ -5,7 +5,7 @@
   <PropertyGroup>
     <Description>Redis storrage support as key store.</Description>
     <VersionPrefix>0.1.0</VersionPrefix>
-    <TargetFrameworks>net451;netstandard1.5</TargetFrameworks>
+    <TargetFrameworks>net46;netstandard1.5</TargetFrameworks>
     <NoWarn>$(NoWarn);CS1591</NoWarn>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
diff --git a/src/Microsoft.AspNetCore.DataProtection.SystemWeb/Microsoft.AspNetCore.DataProtection.SystemWeb.csproj b/src/Microsoft.AspNetCore.DataProtection.SystemWeb/Microsoft.AspNetCore.DataProtection.SystemWeb.csproj
index bc2dc0d8e9..d1ae6aeda7 100644
--- a/src/Microsoft.AspNetCore.DataProtection.SystemWeb/Microsoft.AspNetCore.DataProtection.SystemWeb.csproj
+++ b/src/Microsoft.AspNetCore.DataProtection.SystemWeb/Microsoft.AspNetCore.DataProtection.SystemWeb.csproj
@@ -4,14 +4,14 @@
 
   <PropertyGroup>
     <Description>A component to allow the ASP.NET Core data protection stack to work with the ASP.NET 4.x &lt;machineKey&gt; element.</Description>
-    <TargetFramework>net451</TargetFramework>
+    <TargetFramework>net46</TargetFramework>
     <NoWarn>$(NoWarn);CS1591</NoWarn>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <PackageTags>aspnet;aspnetcore;dataprotection</PackageTags>
   </PropertyGroup>
 
   <ItemGroup>
-    <Content Include="web.config.transform" PackagePath="content/net451/" Pack="true" />
+    <Content Include="web.config.transform" PackagePath="content/net46/" Pack="true" />
   </ItemGroup>
 
   <ItemGroup>
diff --git a/src/Microsoft.AspNetCore.DataProtection/Cng/DpapiSecretSerializerHelper.cs b/src/Microsoft.AspNetCore.DataProtection/Cng/DpapiSecretSerializerHelper.cs
index d007ca4412..ea37a1b989 100644
--- a/src/Microsoft.AspNetCore.DataProtection/Cng/DpapiSecretSerializerHelper.cs
+++ b/src/Microsoft.AspNetCore.DataProtection/Cng/DpapiSecretSerializerHelper.cs
@@ -78,8 +78,11 @@ namespace Microsoft.AspNetCore.DataProtection.Cng
             };
             var dataOut = default(DATA_BLOB);
 
-#if !NETSTANDARD1_3
+#if NET46
             RuntimeHelpers.PrepareConstrainedRegions();
+#elif NETSTANDARD1_3
+#else
+#error target frameworks need to be updated.
 #endif
             try
             {
@@ -168,8 +171,11 @@ namespace Microsoft.AspNetCore.DataProtection.Cng
                     fixed (byte* pbRetVal = retVal)
                     {
                         var handleAcquired = false;
-#if !NETSTANDARD1_3
+#if NET46
                         RuntimeHelpers.PrepareConstrainedRegions();
+#elif NETSTANDARD1_3
+#else
+#error target frameworks need to be updated.
 #endif
                         try
                         {
@@ -218,8 +224,11 @@ namespace Microsoft.AspNetCore.DataProtection.Cng
             };
             var dataOut = default(DATA_BLOB);
 
-#if !NETSTANDARD1_3
+#if NET46
             RuntimeHelpers.PrepareConstrainedRegions();
+#elif NETSTANDARD1_3
+#else
+#error target frameworks need to be updated.
 #endif
             try
             {
@@ -291,8 +300,11 @@ namespace Microsoft.AspNetCore.DataProtection.Cng
             using (unencryptedPayloadHandle)
             {
                 var handleAcquired = false;
-#if !NETSTANDARD1_3
+#if NET46
                 RuntimeHelpers.PrepareConstrainedRegions();
+#elif NETSTANDARD1_3
+#else
+#error target frameworks need to be updated.
 #endif
                 try
                 {
diff --git a/src/Microsoft.AspNetCore.DataProtection/DataProtectionBuilderExtensions.cs b/src/Microsoft.AspNetCore.DataProtection/DataProtectionBuilderExtensions.cs
index e7ca436f6f..6a3a9d459c 100644
--- a/src/Microsoft.AspNetCore.DataProtection/DataProtectionBuilderExtensions.cs
+++ b/src/Microsoft.AspNetCore.DataProtection/DataProtectionBuilderExtensions.cs
@@ -16,7 +16,7 @@ using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
 using Microsoft.Win32;
 
-#if !NETSTANDARD1_3 // [[ISSUE60]] Remove this #ifdef when Core CLR gets support for EncryptedXml
+#if NET46 // [[ISSUE60]] Remove this #ifdef when Core CLR gets support for EncryptedXml
 using System.Security.Cryptography.X509Certificates;
 #endif
 
@@ -249,7 +249,7 @@ namespace Microsoft.AspNetCore.DataProtection
             return builder;
         }
 
-#if !NETSTANDARD1_3 // [[ISSUE60]] Remove this #ifdef when Core CLR gets support for EncryptedXml
+#if NET46 // [[ISSUE60]] Remove this #ifdef when Core CLR gets support for EncryptedXml
 
         /// <summary>
         /// Configures keys to be encrypted to a given certificate before being persisted to storage.
@@ -321,7 +321,9 @@ namespace Microsoft.AspNetCore.DataProtection
 
             return builder;
         }
-
+#elif NETSTANDARD1_3
+#else
+#error target frameworks need to be updated.
 #endif
 
         /// <summary>
diff --git a/src/Microsoft.AspNetCore.DataProtection/DataProtectionServiceCollectionExtensions.cs b/src/Microsoft.AspNetCore.DataProtection/DataProtectionServiceCollectionExtensions.cs
index 3fcaee8f69..4cde160961 100644
--- a/src/Microsoft.AspNetCore.DataProtection/DataProtectionServiceCollectionExtensions.cs
+++ b/src/Microsoft.AspNetCore.DataProtection/DataProtectionServiceCollectionExtensions.cs
@@ -98,8 +98,11 @@ namespace Microsoft.Extensions.DependencyInjection
                 return dataProtectionProvider;
             });
 
-#if !NETSTANDARD1_3 // [[ISSUE60]] Remove this #ifdef when Core CLR gets support for EncryptedXml
+#if NET46 // [[ISSUE60]] Remove this #ifdef when Core CLR gets support for EncryptedXml
             services.TryAddSingleton<ICertificateResolver, CertificateResolver>();
+#elif NETSTANDARD1_3
+#else
+#error target frameworks need to be updated.
 #endif
         }
     }
diff --git a/src/Microsoft.AspNetCore.DataProtection/IDataProtectionBuilder.cs b/src/Microsoft.AspNetCore.DataProtection/IDataProtectionBuilder.cs
index 54539f7b8e..619bdfcad4 100644
--- a/src/Microsoft.AspNetCore.DataProtection/IDataProtectionBuilder.cs
+++ b/src/Microsoft.AspNetCore.DataProtection/IDataProtectionBuilder.cs
@@ -7,7 +7,7 @@ using Microsoft.Extensions.DependencyInjection;
 
 namespace Microsoft.AspNetCore.DataProtection
 {
-#if !NETSTANDARD1_3
+#if NET46
     /// <summary>
     /// Provides access to configuration for the data protection system, which allows the
     /// developer to configure default cryptographic algorithms, key storage locations,
@@ -34,7 +34,7 @@ namespace Microsoft.AspNetCore.DataProtection
     /// contain existing keys that use older algorithms or protection mechanisms.
     /// </para>
     /// </remarks>
-#else
+#elif NETSTANDARD1_3
     /// <summary>
     /// Provides access to configuration for the data protection system, which allows the
     /// developer to configure default cryptographic algorithms, key storage locations,
@@ -58,6 +58,8 @@ namespace Microsoft.AspNetCore.DataProtection
     /// contain existing keys that use older algorithms or protection mechanisms.
     /// </para>
     /// </remarks>
+#else
+#error target frameworks need to be updated.
 #endif
     public interface IDataProtectionBuilder
     {
diff --git a/src/Microsoft.AspNetCore.DataProtection/Managed/ManagedAuthenticatedEncryptor.cs b/src/Microsoft.AspNetCore.DataProtection/Managed/ManagedAuthenticatedEncryptor.cs
index 917d01f190..89cc875d10 100644
--- a/src/Microsoft.AspNetCore.DataProtection/Managed/ManagedAuthenticatedEncryptor.cs
+++ b/src/Microsoft.AspNetCore.DataProtection/Managed/ManagedAuthenticatedEncryptor.cs
@@ -343,11 +343,13 @@ namespace Microsoft.AspNetCore.DataProtection.Managed
 
                             using (var validationAlgorithm = CreateValidationAlgorithm(validationSubkey))
                             {
-#if !NETSTANDARD1_3
+#if NET46
                                 // As an optimization, avoid duplicating the underlying buffer if we're on desktop CLR.
                                 var underlyingBuffer = outputStream.GetBuffer();
-#else
+#elif NETSTANDARD1_3
                                 var underlyingBuffer = outputStream.ToArray();
+#else
+#error target frameworks need to be updated.
 #endif
 
                                 var mac = validationAlgorithm.ComputeHash(underlyingBuffer, KEY_MODIFIER_SIZE_IN_BYTES, checked((int)outputStream.Length - KEY_MODIFIER_SIZE_IN_BYTES));
diff --git a/src/Microsoft.AspNetCore.DataProtection/Microsoft.AspNetCore.DataProtection.csproj b/src/Microsoft.AspNetCore.DataProtection/Microsoft.AspNetCore.DataProtection.csproj
index 62c08637af..ccf9d95f42 100644
--- a/src/Microsoft.AspNetCore.DataProtection/Microsoft.AspNetCore.DataProtection.csproj
+++ b/src/Microsoft.AspNetCore.DataProtection/Microsoft.AspNetCore.DataProtection.csproj
@@ -4,7 +4,7 @@
 
   <PropertyGroup>
     <Description>ASP.NET Core logic to protect and unprotect data, similar to DPAPI.</Description>
-    <TargetFrameworks>net451;netstandard1.3</TargetFrameworks>
+    <TargetFrameworks>net46;netstandard1.3</TargetFrameworks>
     <NoWarn>$(NoWarn);CS1591</NoWarn>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
@@ -25,7 +25,7 @@
     <PackageReference Include="Microsoft.Extensions.Options" Version="$(AspNetCoreVersion)" />
   </ItemGroup>
 
-  <ItemGroup Condition=" '$(TargetFramework)' == 'net451' ">
+  <ItemGroup Condition=" '$(TargetFramework)' == 'net46' ">
     <Reference Include="System.Security" />
     <Reference Include="System.Xml" />
     <Reference Include="System.Xml.Linq" />
diff --git a/src/Microsoft.AspNetCore.DataProtection/Repositories/FileSystemXmlRepository.cs b/src/Microsoft.AspNetCore.DataProtection/Repositories/FileSystemXmlRepository.cs
index 696e54bcae..b88f575a03 100644
--- a/src/Microsoft.AspNetCore.DataProtection/Repositories/FileSystemXmlRepository.cs
+++ b/src/Microsoft.AspNetCore.DataProtection/Repositories/FileSystemXmlRepository.cs
@@ -82,7 +82,7 @@ namespace Microsoft.AspNetCore.DataProtection.Repositories
 
         private static DirectoryInfo GetDefaultKeyStorageDirectory()
         {
-#if !NETSTANDARD1_3
+#if NET46
             // Environment.GetFolderPath returns null if the user profile isn't loaded.
             var folderPath = Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData);
             if (!String.IsNullOrEmpty(folderPath))
@@ -93,7 +93,7 @@ namespace Microsoft.AspNetCore.DataProtection.Repositories
             {
                 return null;
             }
-#else
+#elif NETSTANDARD1_3
             // On core CLR, we need to fall back to environment variables.
             DirectoryInfo retVal;
 
@@ -131,6 +131,8 @@ namespace Microsoft.AspNetCore.DataProtection.Repositories
             {
                 return null;
             }
+#else
+#error target frameworks need to be updated.
 #endif
         }
 
diff --git a/src/Microsoft.AspNetCore.DataProtection/XmlEncryption/CertificateResolver.cs b/src/Microsoft.AspNetCore.DataProtection/XmlEncryption/CertificateResolver.cs
index 1116fd4c10..3bf578e14a 100644
--- a/src/Microsoft.AspNetCore.DataProtection/XmlEncryption/CertificateResolver.cs
+++ b/src/Microsoft.AspNetCore.DataProtection/XmlEncryption/CertificateResolver.cs
@@ -1,7 +1,7 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
-#if !NETSTANDARD1_3 // [[ISSUE60]] Remove this #ifdef when Core CLR gets support for EncryptedXml
+#if NET46 // [[ISSUE60]] Remove this #ifdef when Core CLR gets support for EncryptedXml
 
 using System;
 using System.Security.Cryptography.X509Certificates;
@@ -51,5 +51,7 @@ namespace Microsoft.AspNetCore.DataProtection.XmlEncryption
         }
     }
 }
-
+#elif NETSTANDARD1_3
+#else
+#error target frameworks need to be updated.
 #endif
diff --git a/src/Microsoft.AspNetCore.DataProtection/XmlEncryption/CertificateXmlEncryptor.cs b/src/Microsoft.AspNetCore.DataProtection/XmlEncryption/CertificateXmlEncryptor.cs
index 3bf68dcc66..0cbcf30bae 100644
--- a/src/Microsoft.AspNetCore.DataProtection/XmlEncryption/CertificateXmlEncryptor.cs
+++ b/src/Microsoft.AspNetCore.DataProtection/XmlEncryption/CertificateXmlEncryptor.cs
@@ -1,7 +1,7 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
-#if !NETSTANDARD1_3 // [[ISSUE60]] Remove this #ifdef when Core CLR gets support for EncryptedXml
+#if NET46 // [[ISSUE60]] Remove this #ifdef when Core CLR gets support for EncryptedXml
 
 using System;
 using System.Security.Cryptography.X509Certificates;
@@ -147,5 +147,7 @@ namespace Microsoft.AspNetCore.DataProtection.XmlEncryption
         }
     }
 }
-
+#elif NETSTANDARD1_3
+#else
+#error target frameworks need to be updated.
 #endif
diff --git a/src/Microsoft.AspNetCore.DataProtection/XmlEncryption/EncryptedXmlDecryptor.core50.cs b/src/Microsoft.AspNetCore.DataProtection/XmlEncryption/EncryptedXmlDecryptor.core50.cs
index 565c30e297..36bba2fb81 100644
--- a/src/Microsoft.AspNetCore.DataProtection/XmlEncryption/EncryptedXmlDecryptor.core50.cs
+++ b/src/Microsoft.AspNetCore.DataProtection/XmlEncryption/EncryptedXmlDecryptor.core50.cs
@@ -38,5 +38,7 @@ namespace Microsoft.AspNetCore.DataProtection.XmlEncryption
         }
     }
 }
-
+#elif NET46
+#else
+#error target frameworks need to be updated.
 #endif
diff --git a/src/Microsoft.AspNetCore.DataProtection/XmlEncryption/EncryptedXmlDecryptor.cs b/src/Microsoft.AspNetCore.DataProtection/XmlEncryption/EncryptedXmlDecryptor.cs
index eb8d163d45..bfb70d3283 100644
--- a/src/Microsoft.AspNetCore.DataProtection/XmlEncryption/EncryptedXmlDecryptor.cs
+++ b/src/Microsoft.AspNetCore.DataProtection/XmlEncryption/EncryptedXmlDecryptor.cs
@@ -1,7 +1,7 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
-#if !NETSTANDARD1_3 // [[ISSUE60]] Remove this #ifdef when Core CLR gets support for EncryptedXml
+#if NET46 // [[ISSUE60]] Remove this #ifdef when Core CLR gets support for EncryptedXml
 
 using System;
 using System.Security.Cryptography.Xml;
@@ -73,5 +73,7 @@ namespace Microsoft.AspNetCore.DataProtection.XmlEncryption
         }
     }
 }
-
+#elif NETSTANDARD1_3
+#else
+#error target frameworks need to be updated.
 #endif
diff --git a/src/Microsoft.AspNetCore.DataProtection/XmlEncryption/ICertificateResolver.cs b/src/Microsoft.AspNetCore.DataProtection/XmlEncryption/ICertificateResolver.cs
index 9834687d8d..78b629fd2f 100644
--- a/src/Microsoft.AspNetCore.DataProtection/XmlEncryption/ICertificateResolver.cs
+++ b/src/Microsoft.AspNetCore.DataProtection/XmlEncryption/ICertificateResolver.cs
@@ -1,7 +1,7 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
-#if !NETSTANDARD1_3 // [[ISSUE60]] Remove this #ifdef when Core CLR gets support for EncryptedXml
+#if NET46 // [[ISSUE60]] Remove this #ifdef when Core CLR gets support for EncryptedXml
 
 using System.Security.Cryptography.X509Certificates;
 
@@ -20,5 +20,7 @@ namespace Microsoft.AspNetCore.DataProtection.XmlEncryption
         X509Certificate2 ResolveCertificate(string thumbprint);
     }
 }
-
+#elif NETSTANDARD1_3
+#else
+#error target frameworks need to be updated.
 #endif
diff --git a/src/Microsoft.AspNetCore.DataProtection/XmlEncryption/IInternalCertificateXmlEncryptor.cs b/src/Microsoft.AspNetCore.DataProtection/XmlEncryption/IInternalCertificateXmlEncryptor.cs
index 1e3cfeaee0..33761a29ed 100644
--- a/src/Microsoft.AspNetCore.DataProtection/XmlEncryption/IInternalCertificateXmlEncryptor.cs
+++ b/src/Microsoft.AspNetCore.DataProtection/XmlEncryption/IInternalCertificateXmlEncryptor.cs
@@ -1,7 +1,7 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
-#if !NETSTANDARD1_3 // [[ISSUE60]] Remove this #ifdef when Core CLR gets support for EncryptedXml
+#if NET46 // [[ISSUE60]] Remove this #ifdef when Core CLR gets support for EncryptedXml
 
 using System;
 using System.Xml;
@@ -17,5 +17,7 @@ namespace Microsoft.AspNetCore.DataProtection.XmlEncryption
         EncryptedData PerformEncryption(EncryptedXml encryptedXml, XmlElement elementToEncrypt);
     }
 }
-
+#elif NETSTANDARD1_3
+#else
+#error target frameworks need to be updated.
 #endif
diff --git a/src/Microsoft.AspNetCore.DataProtection/XmlEncryption/IInternalEncryptedXmlDecryptor.cs b/src/Microsoft.AspNetCore.DataProtection/XmlEncryption/IInternalEncryptedXmlDecryptor.cs
index 0bdf6680d6..74987d8f60 100644
--- a/src/Microsoft.AspNetCore.DataProtection/XmlEncryption/IInternalEncryptedXmlDecryptor.cs
+++ b/src/Microsoft.AspNetCore.DataProtection/XmlEncryption/IInternalEncryptedXmlDecryptor.cs
@@ -1,7 +1,7 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
-#if !NETSTANDARD1_3 // [[ISSUE60]] Remove this #ifdef when Core CLR gets support for EncryptedXml
+#if NET46 // [[ISSUE60]] Remove this #ifdef when Core CLR gets support for EncryptedXml
 
 using System;
 using System.Security.Cryptography.Xml;
@@ -16,5 +16,7 @@ namespace Microsoft.AspNetCore.DataProtection.XmlEncryption
         void PerformPreDecryptionSetup(EncryptedXml encryptedXml);
     }
 }
-
+#elif NETSTANDARD1_3
+#else
+#error target frameworks need to be updated.
 #endif
diff --git a/src/Microsoft.AspNetCore.DataProtection/XmlEncryption/XmlEncryptionExtensions.cs b/src/Microsoft.AspNetCore.DataProtection/XmlEncryption/XmlEncryptionExtensions.cs
index 073b82386d..59dcfc96e5 100644
--- a/src/Microsoft.AspNetCore.DataProtection/XmlEncryption/XmlEncryptionExtensions.cs
+++ b/src/Microsoft.AspNetCore.DataProtection/XmlEncryption/XmlEncryptionExtensions.cs
@@ -133,7 +133,7 @@ namespace Microsoft.AspNetCore.DataProtection.XmlEncryption
             var memoryStream = new MemoryStream(DEFAULT_BUFFER_SIZE);
             element.Save(memoryStream);
 
-#if !NETSTANDARD1_3
+#if NET46
             var underlyingBuffer = memoryStream.GetBuffer();
             fixed (byte* __unused__ = underlyingBuffer) // try to limit this moving around in memory while we allocate
             {
@@ -146,7 +146,7 @@ namespace Microsoft.AspNetCore.DataProtection.XmlEncryption
                     Array.Clear(underlyingBuffer, 0, underlyingBuffer.Length);
                 }
             }
-#else
+#elif NETSTANDARD1_3
             ArraySegment<byte> underlyingBuffer;
             CryptoUtil.Assert(memoryStream.TryGetBuffer(out underlyingBuffer), "Underlying buffer isn't exposable.");
             fixed (byte* __unused__ = underlyingBuffer.Array) // try to limit this moving around in memory while we allocate
@@ -160,6 +160,8 @@ namespace Microsoft.AspNetCore.DataProtection.XmlEncryption
                     Array.Clear(underlyingBuffer.Array, underlyingBuffer.Offset, underlyingBuffer.Count);
                 }
             }
+#else
+#error target frameworks need to be updated.
 #endif
         }
 
diff --git a/test/Microsoft.AspNetCore.Cryptography.Internal.Test/Microsoft.AspNetCore.Cryptography.Internal.Test.csproj b/test/Microsoft.AspNetCore.Cryptography.Internal.Test/Microsoft.AspNetCore.Cryptography.Internal.Test.csproj
index 71a60ea4d8..6e44f5d7c3 100644
--- a/test/Microsoft.AspNetCore.Cryptography.Internal.Test/Microsoft.AspNetCore.Cryptography.Internal.Test.csproj
+++ b/test/Microsoft.AspNetCore.Cryptography.Internal.Test/Microsoft.AspNetCore.Cryptography.Internal.Test.csproj
@@ -3,10 +3,9 @@
   <Import Project="..\..\build\common.props" />
 
   <PropertyGroup>
-    <TargetFrameworks>netcoreapp2.0;net452</TargetFrameworks>
+    <TargetFrameworks>netcoreapp2.0;net46</TargetFrameworks>
     <TargetFrameworks Condition=" '$(OS)' != 'Windows_NT' ">netcoreapp2.0</TargetFrameworks>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-    <PackageTargetFallback Condition=" '$(TargetFramework)' == 'netcoreapp2.0' ">$(PackageTargetFallback);dnxcore50;portable-net451+win8</PackageTargetFallback>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/test/Microsoft.AspNetCore.Cryptography.KeyDerivation.Test/Microsoft.AspNetCore.Cryptography.KeyDerivation.Test.csproj b/test/Microsoft.AspNetCore.Cryptography.KeyDerivation.Test/Microsoft.AspNetCore.Cryptography.KeyDerivation.Test.csproj
index 56b23f29fd..4fec4fa063 100644
--- a/test/Microsoft.AspNetCore.Cryptography.KeyDerivation.Test/Microsoft.AspNetCore.Cryptography.KeyDerivation.Test.csproj
+++ b/test/Microsoft.AspNetCore.Cryptography.KeyDerivation.Test/Microsoft.AspNetCore.Cryptography.KeyDerivation.Test.csproj
@@ -3,7 +3,7 @@
   <Import Project="..\..\build\common.props" />
 
   <PropertyGroup>
-    <TargetFrameworks>netcoreapp2.0;net452</TargetFrameworks>
+    <TargetFrameworks>netcoreapp2.0;net46</TargetFrameworks>
     <TargetFrameworks Condition=" '$(OS)' != 'Windows_NT' ">netcoreapp2.0</TargetFrameworks>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
   </PropertyGroup>
diff --git a/test/Microsoft.AspNetCore.DataProtection.Abstractions.Test/Microsoft.AspNetCore.DataProtection.Abstractions.Test.csproj b/test/Microsoft.AspNetCore.DataProtection.Abstractions.Test/Microsoft.AspNetCore.DataProtection.Abstractions.Test.csproj
index 076480457b..8a478b5dd2 100644
--- a/test/Microsoft.AspNetCore.DataProtection.Abstractions.Test/Microsoft.AspNetCore.DataProtection.Abstractions.Test.csproj
+++ b/test/Microsoft.AspNetCore.DataProtection.Abstractions.Test/Microsoft.AspNetCore.DataProtection.Abstractions.Test.csproj
@@ -3,7 +3,7 @@
   <Import Project="..\..\build\common.props" />
 
   <PropertyGroup>
-    <TargetFrameworks>netcoreapp2.0;net452</TargetFrameworks>
+    <TargetFrameworks>netcoreapp2.0;net46</TargetFrameworks>
     <TargetFrameworks Condition=" '$(OS)' != 'Windows_NT' ">netcoreapp2.0</TargetFrameworks>
   </PropertyGroup>
 
diff --git a/test/Microsoft.AspNetCore.DataProtection.AzureStorage.Test/Microsoft.AspNetCore.DataProtection.AzureStorage.Test.csproj b/test/Microsoft.AspNetCore.DataProtection.AzureStorage.Test/Microsoft.AspNetCore.DataProtection.AzureStorage.Test.csproj
index fb2b75b60a..c0432a5da6 100644
--- a/test/Microsoft.AspNetCore.DataProtection.AzureStorage.Test/Microsoft.AspNetCore.DataProtection.AzureStorage.Test.csproj
+++ b/test/Microsoft.AspNetCore.DataProtection.AzureStorage.Test/Microsoft.AspNetCore.DataProtection.AzureStorage.Test.csproj
@@ -3,7 +3,7 @@
   <Import Project="..\..\build\common.props" />
 
   <PropertyGroup>
-    <TargetFrameworks>netcoreapp2.0;net452</TargetFrameworks>
+    <TargetFrameworks>netcoreapp2.0;net46</TargetFrameworks>
     <TargetFrameworks Condition=" '$(OS)' != 'Windows_NT' ">netcoreapp2.0</TargetFrameworks>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <PackageTargetFallback Condition=" '$(TargetFramework)' == 'netcoreapp2.0' ">$(PackageTargetFallback);dnxcore50;portable-net451+win8</PackageTargetFallback>
diff --git a/test/Microsoft.AspNetCore.DataProtection.Extensions.Test/DataProtectionProviderTests.cs b/test/Microsoft.AspNetCore.DataProtection.Extensions.Test/DataProtectionProviderTests.cs
index 694b612ce1..d23d088d87 100644
--- a/test/Microsoft.AspNetCore.DataProtection.Extensions.Test/DataProtectionProviderTests.cs
+++ b/test/Microsoft.AspNetCore.DataProtection.Extensions.Test/DataProtectionProviderTests.cs
@@ -106,7 +106,7 @@ namespace Microsoft.AspNetCore.DataProtection
             });
         }
 
-#if NET452 // [[ISSUE60]] Remove this #ifdef when Core CLR gets support for EncryptedXml
+#if NET46 // [[ISSUE60]] Remove this #ifdef when Core CLR gets support for EncryptedXml
         [ConditionalFact]
         [ConditionalRunTestOnlyIfLocalAppDataAvailable]
         [ConditionalRunTestOnlyOnWindows]
diff --git a/test/Microsoft.AspNetCore.DataProtection.Extensions.Test/Microsoft.AspNetCore.DataProtection.Extensions.Test.csproj b/test/Microsoft.AspNetCore.DataProtection.Extensions.Test/Microsoft.AspNetCore.DataProtection.Extensions.Test.csproj
index 4dc5e85324..70bbf78e0c 100644
--- a/test/Microsoft.AspNetCore.DataProtection.Extensions.Test/Microsoft.AspNetCore.DataProtection.Extensions.Test.csproj
+++ b/test/Microsoft.AspNetCore.DataProtection.Extensions.Test/Microsoft.AspNetCore.DataProtection.Extensions.Test.csproj
@@ -3,7 +3,7 @@
   <Import Project="..\..\build\common.props" />
 
   <PropertyGroup>
-    <TargetFrameworks>netcoreapp2.0;net452</TargetFrameworks>
+    <TargetFrameworks>netcoreapp2.0;net46</TargetFrameworks>
     <TargetFrameworks Condition=" '$(OS)' != 'Windows_NT' ">netcoreapp2.0</TargetFrameworks>
   </PropertyGroup>
 
diff --git a/test/Microsoft.AspNetCore.DataProtection.Redis.Test/Microsoft.AspNetCore.DataProtection.Redis.Test.csproj b/test/Microsoft.AspNetCore.DataProtection.Redis.Test/Microsoft.AspNetCore.DataProtection.Redis.Test.csproj
index f873d70e1d..8f86aafb2a 100644
--- a/test/Microsoft.AspNetCore.DataProtection.Redis.Test/Microsoft.AspNetCore.DataProtection.Redis.Test.csproj
+++ b/test/Microsoft.AspNetCore.DataProtection.Redis.Test/Microsoft.AspNetCore.DataProtection.Redis.Test.csproj
@@ -3,7 +3,7 @@
   <Import Project="..\..\build\common.props" />
 
   <PropertyGroup>
-    <TargetFrameworks>netcoreapp2.0;net452</TargetFrameworks>
+    <TargetFrameworks>netcoreapp2.0;net46</TargetFrameworks>
     <TargetFrameworks Condition=" '$(OS)' != 'Windows_NT' ">netcoreapp2.0</TargetFrameworks>
   </PropertyGroup>
 
diff --git a/test/Microsoft.AspNetCore.DataProtection.Test/AnonymousImpersonation.cs b/test/Microsoft.AspNetCore.DataProtection.Test/AnonymousImpersonation.cs
index 89f115beba..ec61427bb2 100644
--- a/test/Microsoft.AspNetCore.DataProtection.Test/AnonymousImpersonation.cs
+++ b/test/Microsoft.AspNetCore.DataProtection.Test/AnonymousImpersonation.cs
@@ -1,7 +1,7 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
-#if NET452
+#if NET46
 using System;
 using System.Runtime.ConstrainedExecution;
 using System.Runtime.InteropServices;
diff --git a/test/Microsoft.AspNetCore.DataProtection.Test/Microsoft.AspNetCore.DataProtection.Test.csproj b/test/Microsoft.AspNetCore.DataProtection.Test/Microsoft.AspNetCore.DataProtection.Test.csproj
index e5f8052014..724912b1f5 100644
--- a/test/Microsoft.AspNetCore.DataProtection.Test/Microsoft.AspNetCore.DataProtection.Test.csproj
+++ b/test/Microsoft.AspNetCore.DataProtection.Test/Microsoft.AspNetCore.DataProtection.Test.csproj
@@ -3,7 +3,7 @@
   <Import Project="..\..\build\common.props" />
 
   <PropertyGroup>
-    <TargetFrameworks>netcoreapp2.0;net452</TargetFrameworks>
+    <TargetFrameworks>netcoreapp2.0;net46</TargetFrameworks>
     <TargetFrameworks Condition=" '$(OS)' != 'Windows_NT' ">netcoreapp2.0</TargetFrameworks>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
   </PropertyGroup>
@@ -22,7 +22,7 @@
     <PackageReference Include="xunit" Version="$(XunitVersion)" />
   </ItemGroup>
 
-  <ItemGroup Condition="'$(TargetFramework)'=='net452'">
+  <ItemGroup Condition="'$(TargetFramework)'=='net46'">
     <Reference Include="System.Security" />
   </ItemGroup>
 
diff --git a/test/Microsoft.AspNetCore.DataProtection.Test/Repositories/FileSystemXmlRepositoryTests.cs b/test/Microsoft.AspNetCore.DataProtection.Test/Repositories/FileSystemXmlRepositoryTests.cs
index bb371dd889..a6a1f7896b 100644
--- a/test/Microsoft.AspNetCore.DataProtection.Test/Repositories/FileSystemXmlRepositoryTests.cs
+++ b/test/Microsoft.AspNetCore.DataProtection.Test/Repositories/FileSystemXmlRepositoryTests.cs
@@ -161,7 +161,7 @@ namespace Microsoft.AspNetCore.DataProtection.Repositories
         {
 #if NETCOREAPP2_0
             return Environment.GetEnvironmentVariable("LOCALAPPDATA");
-#elif NET452
+#elif NET46
             return Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData);
 #else
 #error Target framework needs to be updated
diff --git a/test/Microsoft.AspNetCore.DataProtection.Test/XmlEncryption/CertificateXmlEncryptionTests.cs b/test/Microsoft.AspNetCore.DataProtection.Test/XmlEncryption/CertificateXmlEncryptionTests.cs
index 0dd9e072c2..a70e908b9d 100644
--- a/test/Microsoft.AspNetCore.DataProtection.Test/XmlEncryption/CertificateXmlEncryptionTests.cs
+++ b/test/Microsoft.AspNetCore.DataProtection.Test/XmlEncryption/CertificateXmlEncryptionTests.cs
@@ -1,7 +1,7 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
-#if NET452
+#if NET46
 using System;
 using System.Security.Cryptography;
 using System.Security.Cryptography.Xml;
diff --git a/test/Microsoft.AspNetCore.DataProtection.Test/XmlEncryption/DpapiXmlEncryptionTests.cs b/test/Microsoft.AspNetCore.DataProtection.Test/XmlEncryption/DpapiXmlEncryptionTests.cs
index bcb41921d5..828761b430 100644
--- a/test/Microsoft.AspNetCore.DataProtection.Test/XmlEncryption/DpapiXmlEncryptionTests.cs
+++ b/test/Microsoft.AspNetCore.DataProtection.Test/XmlEncryption/DpapiXmlEncryptionTests.cs
@@ -34,7 +34,7 @@ namespace Microsoft.AspNetCore.DataProtection.XmlEncryption
             XmlAssert.Equal(originalXml, roundTrippedElement);
         }
 
-#if NET452
+#if NET46
         [ConditionalFact]
         [ConditionalRunTestOnlyOnWindows]
         public void Encrypt_CurrentUser_Decrypt_ImpersonatedAsAnonymous_Fails()