diff --git a/MaterialDesignExtensions/Converters/FileSystemInfoIconConverter.cs b/MaterialDesignExtensions/Converters/FileSystemInfoIconConverter.cs
index a85eb163..942c0104 100644
--- a/MaterialDesignExtensions/Converters/FileSystemInfoIconConverter.cs
+++ b/MaterialDesignExtensions/Converters/FileSystemInfoIconConverter.cs
@@ -24,8 +24,8 @@ namespace MaterialDesignExtensions.Converters
     /// </summary>
     public class FileSystemInfoIconConverter : IValueConverter
     {
-        private ISet<string> m_imageFileExtensions;
-        private IDictionary<string, object> m_contentForFileExtension;
+        private readonly ISet<string> m_imageFileExtensions;
+        private readonly IDictionary<string, object> m_contentForFileExtension;
 
         /// <summary>
         /// The content mode to control the type of icons or thumbnails for image file types.
@@ -131,7 +131,6 @@ public FileSystemInfoIconConverter()
                 ["wmv"] = PackIconKind.FileVideo,
                 ["flv"] = PackIconKind.FileVideo,
                 ["avi"] = PackIconKind.FileVideo,
-                ["flv"] = PackIconKind.FileVideo,
                 ["mov"] = PackIconKind.FileVideo,
                 ["webm"] = PackIconKind.FileVideo,
                 ["mkv"] = PackIconKind.FileVideo,
@@ -150,7 +149,7 @@ public FileSystemInfoIconConverter()
                 ["pptx"] = PackIconKind.FilePowerpoint,
                 ["ppt"] = PackIconKind.FilePowerpoint,
                 ["pps"] = PackIconKind.FilePowerpoint,
-                ["pdf"] = PackIconKind.FilePdf,
+                ["pdf"] = PackIconKind.FilePdfBox,
                 ["txt"] = PackIconKind.FileDocument,
                 ["rtf"] = PackIconKind.FileDocument
             };
@@ -163,7 +162,7 @@ public FileSystemInfoIconConverter()
 
         public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
         {
-            if (value is DirectoryInfo directory)
+            if (value is DirectoryInfo _)
             {
                 return PackIconKind.Folder;
             }
diff --git a/MaterialDesignExtensions/Converters/FileSystemInfoPackIconColorConverter.cs b/MaterialDesignExtensions/Converters/FileSystemInfoPackIconColorConverter.cs
index def2f44b..3f6edbbc 100644
--- a/MaterialDesignExtensions/Converters/FileSystemInfoPackIconColorConverter.cs
+++ b/MaterialDesignExtensions/Converters/FileSystemInfoPackIconColorConverter.cs
@@ -16,7 +16,7 @@ namespace MaterialDesignExtensions.Converters
     /// </summary>
     public class FileSystemInfoPackIconColorConverter : IValueConverter
     {
-        private IDictionary<PackIconKind, Brush> m_brushesForPackIcon;
+        private readonly IDictionary<PackIconKind, Brush> m_brushesForPackIcon;
 
         /// <summary>
         /// Creates a new <see cref="FileSystemInfoPackIconColorConverter" />.
@@ -34,7 +34,7 @@ public FileSystemInfoPackIconColorConverter()
                 [PackIconKind.FileWord] = new SolidColorBrush((Color)ColorConverter.ConvertFromString("#2196F3")),
                 [PackIconKind.FileExcel] = new SolidColorBrush((Color)ColorConverter.ConvertFromString("#186C3F")),
                 [PackIconKind.FilePowerpoint] = new SolidColorBrush((Color)ColorConverter.ConvertFromString("#FF9800")),
-                [PackIconKind.FilePdf] = new SolidColorBrush((Color)ColorConverter.ConvertFromString("#F44336"))
+                [PackIconKind.FilePdfBox] = new SolidColorBrush((Color)ColorConverter.ConvertFromString("#F44336"))
             };
         }
 
diff --git a/MaterialDesignExtensions/MaterialDesignExtensions.csproj b/MaterialDesignExtensions/MaterialDesignExtensions.csproj
index 8ac2cc5f..4451f03c 100644
--- a/MaterialDesignExtensions/MaterialDesignExtensions.csproj
+++ b/MaterialDesignExtensions/MaterialDesignExtensions.csproj
@@ -1,8 +1,8 @@
 <?xml version="1.0" encoding="utf-8"?>
-<Project Sdk="Microsoft.NET.Sdk.WindowsDesktop">
+<Project Sdk="Microsoft.NET.Sdk">
   
   <PropertyGroup>
-    <TargetFrameworks>net452;netcoreapp3.1</TargetFrameworks>
+    <TargetFrameworks>net452;netcoreapp3.1;net5.0-windows;net6.0-windows</TargetFrameworks>
     <UseWPF>true</UseWPF>
     <AssemblyTitle>Material Design Extensions</AssemblyTitle>
     <Summary>Material Design Extensions is based on Material Design in XAML Toolkit to provide additional controls and features for WPF apps. The controls might not be specified in the Material Design specification or would crash the scope of Material Design in XAML Toolkit.</Summary>
@@ -33,8 +33,8 @@ Important notice: The configuration for version 2.6.0 changed. See the release n
   </PropertyGroup>
   
   <ItemGroup>
-    <PackageReference Include="MaterialDesignColors" Version="2.0.1" />
-    <PackageReference Include="MaterialDesignThemes" Version="4.1.0" />
+    <PackageReference Include="MaterialDesignColors" Version="2.0.4" />
+    <PackageReference Include="MaterialDesignThemes" Version="4.3.0" />
   </ItemGroup>
 
   <ItemGroup>
diff --git a/MaterialDesignExtensionsBuildUtility/MaterialDesignExtensionsBuildUtility.csproj b/MaterialDesignExtensionsBuildUtility/MaterialDesignExtensionsBuildUtility.csproj
index 4650a337..c68ebceb 100644
--- a/MaterialDesignExtensionsBuildUtility/MaterialDesignExtensionsBuildUtility.csproj
+++ b/MaterialDesignExtensionsBuildUtility/MaterialDesignExtensionsBuildUtility.csproj
@@ -3,7 +3,7 @@
   
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>netcoreapp3.1</TargetFramework>
+    <TargetFramework>net6.0</TargetFramework>
     <GenerateAssemblyInfo>false</GenerateAssemblyInfo>
   </PropertyGroup>
   
diff --git a/MaterialDesignExtensionsDemo/MaterialDesignExtensionsDemo.csproj b/MaterialDesignExtensionsDemo/MaterialDesignExtensionsDemo.csproj
index 9e7b1562..63d4f6b1 100644
--- a/MaterialDesignExtensionsDemo/MaterialDesignExtensionsDemo.csproj
+++ b/MaterialDesignExtensionsDemo/MaterialDesignExtensionsDemo.csproj
@@ -1,10 +1,10 @@
 <?xml version="1.0" encoding="utf-8"?>
-<Project Sdk="Microsoft.NET.Sdk.WindowsDesktop">
+<Project Sdk="Microsoft.NET.Sdk">
   
   <PropertyGroup>
     <OutputType>WinExe</OutputType>
     <!--<TargetFramework>net472</TargetFramework>-->
-    <TargetFramework>netcoreapp3.1</TargetFramework>
+    <TargetFramework>net6.0-windows</TargetFramework>
     <UseWPF>true</UseWPF>
     <GenerateAssemblyInfo>false</GenerateAssemblyInfo>
   </PropertyGroup>
@@ -14,8 +14,8 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="MaterialDesignColors" Version="2.0.1" />
-    <PackageReference Include="MaterialDesignThemes" Version="4.1.0" />
+    <PackageReference Include="MaterialDesignColors" Version="2.0.4" />
+    <PackageReference Include="MaterialDesignThemes" Version="4.3.0" />
   </ItemGroup>
 
   <PropertyGroup>
diff --git a/MaterialDesignExtensionsTests/MaterialDesignExtensionsTests.csproj b/MaterialDesignExtensionsTests/MaterialDesignExtensionsTests.csproj
index 895be74a..73177e5f 100644
--- a/MaterialDesignExtensionsTests/MaterialDesignExtensionsTests.csproj
+++ b/MaterialDesignExtensionsTests/MaterialDesignExtensionsTests.csproj
@@ -2,13 +2,13 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>netcoreapp3.1</TargetFramework>
+    <TargetFramework>net6.0-windows</TargetFramework>
     <GenerateAssemblyInfo>false</GenerateAssemblyInfo>
     <IsPackable>false</IsPackable>
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.7.1" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.0.0" />
     <PackageReference Include="xunit" Version="2.4.1" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.4.3">
       <PrivateAssets>all</PrivateAssets>