diff --git a/src/ImageSharp.Drawing/ImageSharp.Drawing.csproj b/src/ImageSharp.Drawing/ImageSharp.Drawing.csproj
index 6341e1771c..1cb3f444f0 100644
--- a/src/ImageSharp.Drawing/ImageSharp.Drawing.csproj
+++ b/src/ImageSharp.Drawing/ImageSharp.Drawing.csproj
@@ -5,8 +5,7 @@
         <VersionPrefix Condition="$(packageversion) != ''">$(packageversion)</VersionPrefix>
         <VersionPrefix Condition="$(packageversion) == ''">0.0.1</VersionPrefix>
         <Authors>SixLabors and contributors</Authors>
-        <!--<TargetFrameworks>netstandard1.3;netstandard2.0</TargetFrameworks>-->
-        <TargetFramework>netcoreapp2.1</TargetFramework>
+        <TargetFrameworks>netstandard1.3;netstandard2.0</TargetFrameworks>
         <LangVersion>7.3</LangVersion>
         <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
         <GenerateDocumentationFile>true</GenerateDocumentationFile>
diff --git a/src/ImageSharp/ImageSharp.csproj b/src/ImageSharp/ImageSharp.csproj
index e2f55e3c6a..29d29d50d8 100644
--- a/src/ImageSharp/ImageSharp.csproj
+++ b/src/ImageSharp/ImageSharp.csproj
@@ -5,8 +5,7 @@
     <VersionPrefix Condition="$(packageversion) != ''">$(packageversion)</VersionPrefix>
     <VersionPrefix Condition="$(packageversion) == ''">0.0.1</VersionPrefix>
     <Authors>Six Labors and contributors</Authors>
-    <!--<TargetFrameworks>netstandard1.3;netstandard2.0;netcoreapp2.1;net472</TargetFrameworks>-->
-    <TargetFramework>netcoreapp2.1</TargetFramework>
+    <TargetFrameworks>netstandard1.3;netstandard2.0;netcoreapp2.1;net472</TargetFrameworks>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <AssemblyName>SixLabors.ImageSharp</AssemblyName>
diff --git a/src/ImageSharp/Processing/Processors/Transforms/Resize/ResizeKernelMap.MosaicKernelMap.cs b/src/ImageSharp/Processing/Processors/Transforms/Resize/ResizeKernelMap.PeriodicKernelMap.cs
similarity index 94%
rename from src/ImageSharp/Processing/Processors/Transforms/Resize/ResizeKernelMap.MosaicKernelMap.cs
rename to src/ImageSharp/Processing/Processors/Transforms/Resize/ResizeKernelMap.PeriodicKernelMap.cs
index e106b1ea0a..b7b581c185 100644
--- a/src/ImageSharp/Processing/Processors/Transforms/Resize/ResizeKernelMap.MosaicKernelMap.cs
+++ b/src/ImageSharp/Processing/Processors/Transforms/Resize/ResizeKernelMap.PeriodicKernelMap.cs
@@ -8,20 +8,20 @@ using SixLabors.Memory;
 namespace SixLabors.ImageSharp.Processing.Processors.Transforms
 {
     /// <content>
-    /// Contains <see cref="MosaicKernelMap"/>
+    /// Contains <see cref="PeriodicKernelMap"/>
     /// </content>
     internal partial class ResizeKernelMap
     {
         /// <summary>
         /// Memory-optimized <see cref="ResizeKernelMap"/> where repeating rows are stored only once.
         /// </summary>
-        private sealed class MosaicKernelMap : ResizeKernelMap
+        private sealed class PeriodicKernelMap : ResizeKernelMap
         {
             private readonly int period;
 
             private readonly int cornerInterval;
 
-            public MosaicKernelMap(
+            public PeriodicKernelMap(
                 MemoryAllocator memoryAllocator,
                 IResampler sampler,
                 int sourceLength,
diff --git a/src/ImageSharp/Processing/Processors/Transforms/Resize/ResizeKernelMap.cs b/src/ImageSharp/Processing/Processors/Transforms/Resize/ResizeKernelMap.cs
index ccb57114ae..011a4ffa22 100644
--- a/src/ImageSharp/Processing/Processors/Transforms/Resize/ResizeKernelMap.cs
+++ b/src/ImageSharp/Processing/Processors/Transforms/Resize/ResizeKernelMap.cs
@@ -118,7 +118,7 @@ namespace SixLabors.ImageSharp.Processing.Processors.Transforms
             bool useMosaic = 2 * (cornerInterval + period) < destinationSize;
 
             ResizeKernelMap result = useMosaic
-                                         ? new MosaicKernelMap(
+                                         ? new PeriodicKernelMap(
                                              memoryAllocator,
                                              sampler,
                                              sourceSize,
diff --git a/tests/ImageSharp.Benchmarks/ImageSharp.Benchmarks.csproj b/tests/ImageSharp.Benchmarks/ImageSharp.Benchmarks.csproj
index 04a4541b21..a705c9bacb 100644
--- a/tests/ImageSharp.Benchmarks/ImageSharp.Benchmarks.csproj
+++ b/tests/ImageSharp.Benchmarks/ImageSharp.Benchmarks.csproj
@@ -1,7 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <!--<TargetFrameworks>netcoreapp2.1;net461</TargetFrameworks>-->
-    <TargetFramework>netcoreapp2.1</TargetFramework>
+    <TargetFrameworks>netcoreapp2.1;net461</TargetFrameworks>
     <OutputType>Exe</OutputType>
     <AllowUnsafeBlocks>True</AllowUnsafeBlocks>
     <RootNamespace>SixLabors.ImageSharp.Benchmarks</RootNamespace>
diff --git a/tests/ImageSharp.Tests/ImageSharp.Tests.csproj b/tests/ImageSharp.Tests/ImageSharp.Tests.csproj
index 75ac7450c8..86c1a7a259 100644
--- a/tests/ImageSharp.Tests/ImageSharp.Tests.csproj
+++ b/tests/ImageSharp.Tests/ImageSharp.Tests.csproj
@@ -1,7 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <!--<TargetFrameworks>net462;net472;netcoreapp2.1</TargetFrameworks>-->
-    <TargetFramework>netcoreapp2.1</TargetFramework>
+    <TargetFrameworks>net462;net472;netcoreapp2.1</TargetFrameworks>
     <AllowUnsafeBlocks>True</AllowUnsafeBlocks>
     <LangVersion>latest</LangVersion>
     <DebugType Condition="$(codecov) != ''">full</DebugType>
diff --git a/tests/ImageSharp.Tests/Processing/Processors/Transforms/KernelMapTests.ReferenceKernelMap.cs b/tests/ImageSharp.Tests/Processing/Processors/Transforms/KernelMapTests.ReferenceKernelMap.cs
index f7c3b27e5a..12c7016096 100644
--- a/tests/ImageSharp.Tests/Processing/Processors/Transforms/KernelMapTests.ReferenceKernelMap.cs
+++ b/tests/ImageSharp.Tests/Processing/Processors/Transforms/KernelMapTests.ReferenceKernelMap.cs
@@ -33,7 +33,7 @@ namespace SixLabors.ImageSharp.Tests.Processing.Processors.Transforms
                     scale = 1F;
                 }
 
-                float radius = MathF.Ceiling(scale * sampler.Radius);
+                float radius = (float)Math.Ceiling(scale * sampler.Radius);
                 
                 var result = new List<ReferenceKernel>();
 
@@ -42,13 +42,13 @@ namespace SixLabors.ImageSharp.Tests.Processing.Processors.Transforms
                     float center = ((i + .5F) * ratio) - .5F;
 
                     // Keep inside bounds.
-                    int left = (int)MathF.Ceiling(center - radius);
+                    int left = (int)Math.Ceiling(center - radius);
                     if (left < 0)
                     {
                         left = 0;
                     }
 
-                    int right = (int)MathF.Floor(center + radius);
+                    int right = (int)Math.Floor(center + radius);
                     if (right > sourceSize - 1)
                     {
                         right = sourceSize - 1;
diff --git a/tests/ImageSharp.Tests/Processing/Processors/Transforms/KernelMapTests.cs b/tests/ImageSharp.Tests/Processing/Processors/Transforms/KernelMapTests.cs
index af98b99521..962c599e6a 100644
--- a/tests/ImageSharp.Tests/Processing/Processors/Transforms/KernelMapTests.cs
+++ b/tests/ImageSharp.Tests/Processing/Processors/Transforms/KernelMapTests.cs
@@ -1,12 +1,11 @@
-using System;
-using System.IO;
-using System.Runtime.InteropServices;
+// Copyright (c) Six Labors and contributors.
+// Licensed under the Apache License, Version 2.0.
+
+using System;
 using System.Text;
 
-using SixLabors.ImageSharp.PixelFormats;
 using SixLabors.ImageSharp.Processing;
 using SixLabors.ImageSharp.Processing.Processors.Transforms;
-using SixLabors.Primitives;
 
 using Xunit;
 using Xunit.Abstractions;