diff --git a/Generate-ReleaseNotes.bat b/Generate-ReleaseNotes.bat
index 69a1974..9f7365d 100644
--- a/Generate-ReleaseNotes.bat
+++ b/Generate-ReleaseNotes.bat
@@ -1,6 +1,6 @@
 rem https://github.com/StefH/GitHubReleaseNotes
 
-SET version=0.0.20
+SET version=0.0.21
 
 GitHubReleaseNotes --output "ReleaseNotes.md" --skip-empty-releases --exclude-labels question invalid doc --version %version%
 
diff --git a/resources/icon.png b/resources/icon.png
new file mode 100644
index 0000000..65e107f
Binary files /dev/null and b/resources/icon.png differ
diff --git a/src/ProxyInterfaceSourceGenerator/Extensions/ParameterSymbolExtensions.cs b/src/ProxyInterfaceSourceGenerator/Extensions/ParameterSymbolExtensions.cs
index e7a6bee..1d32edd 100644
--- a/src/ProxyInterfaceSourceGenerator/Extensions/ParameterSymbolExtensions.cs
+++ b/src/ProxyInterfaceSourceGenerator/Extensions/ParameterSymbolExtensions.cs
@@ -6,25 +6,17 @@ namespace ProxyInterfaceSourceGenerator.Extensions;
 
 internal static class ParameterSymbolExtensions
 {
-    // private const string ParameterValueDefault = "default";
     private const string ParameterValueNull = "null";
 
     public static string GetRefPrefix(this IParameterSymbol ps)
     {
-        switch (ps.RefKind)
+        return ps.RefKind switch
         {
-            case RefKind.In:
-                return "in ";
-
-            case RefKind.Out:
-                return "out ";
-
-            case RefKind.Ref:
-                return "ref ";
-
-            default:
-                return string.Empty;
-        }
+            RefKind.In => "in ",
+            RefKind.Out => "out ",
+            RefKind.Ref => "ref ",
+            _ => string.Empty
+        };
     }
 
     public static string GetParamsPrefix(this IParameterSymbol ps) =>
@@ -40,7 +32,17 @@ internal static class ParameterSymbolExtensions
         string defaultValue;
         if (ps.ExplicitDefaultValue == null)
         {
-            defaultValue = ps.Type.IsReferenceType ? ParameterValueNull : $"default({ps.Type})";
+            if (ps.NullableAnnotation == NullableAnnotation.Annotated)
+            {
+                // The parameter is defined as Nullable, so always use "null".
+                defaultValue = ParameterValueNull;
+            }
+            else
+            {
+                defaultValue = ps.Type.IsReferenceType
+                    ? ParameterValueNull : // The parameter is a ReferenceType, so use "null".
+                    $"default({ps.Type})"; // The parameter is not a ReferenceType, so use "default(T)".
+            }
         }
         else
         {
diff --git a/src/ProxyInterfaceSourceGenerator/ProxyInterfaceSourceGenerator.csproj b/src/ProxyInterfaceSourceGenerator/ProxyInterfaceSourceGenerator.csproj
index d178ced..35bee15 100644
--- a/src/ProxyInterfaceSourceGenerator/ProxyInterfaceSourceGenerator.csproj
+++ b/src/ProxyInterfaceSourceGenerator/ProxyInterfaceSourceGenerator.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
     <PropertyGroup>
-        <Version>0.0.20</Version>
+        <Version>0.0.21</Version>
         <TargetFramework>netstandard2.0</TargetFramework>
         <ProjectGuid>{12344228-91F4-4502-9595-39584E5ABB34}</ProjectGuid>
         <LangVersion>10</LangVersion>
@@ -12,14 +12,13 @@
         <PackageId>ProxyInterfaceGenerator</PackageId>
         <Description>This project uses Source Generation to generate an interface and a Proxy class for classes. This makes it possible to wrap external classes which do not have an interface, in a Proxy class which makes it easier to Mock and use DI.</Description>
         <PackageTags>class;interface;proxy;SourceGenerator;Analyzer;Generation;Generate;wrap</PackageTags>
-
         <PackageLicenseExpression>MIT</PackageLicenseExpression>
         <PackageReleaseNotes>$([System.IO.File]::ReadAllText("$(MSBuildProjectDirectory)/../../PackageReleaseNotes.txt"))</PackageReleaseNotes>
         <PackageProjectUrl>https://github.com/StefH/ProxyInterfaceGenerator</PackageProjectUrl>
         <RepositoryType>git</RepositoryType>
         <RepositoryUrl>https://github.com/StefH/ProxyInterfaceGenerator</RepositoryUrl>
         <PackageReadmeFile>PackageReadme.md</PackageReadmeFile>
-
+        <PackageIcon>icon.png</PackageIcon>
         <IncludeBuildOutput>false</IncludeBuildOutput>
         <EmitCompilerGeneratedFiles>true</EmitCompilerGeneratedFiles>
         <CompilerGeneratedFilesOutputPath>$(BaseIntermediateOutputPath)Generated</CompilerGeneratedFilesOutputPath>
@@ -33,32 +32,31 @@
     </PropertyGroup>
 
     <ItemGroup>
+        <None Include="../../resources/icon.png" Pack="true" PackagePath="" />
         <None Include="../../PackageReadme.md" Pack="true" PackagePath="" />
     </ItemGroup>
 
     <ItemGroup>
-        <!--<PackageReference Include="AutoMapper" Version="10.1.1" />-->
         <PackageReference Include="Microsoft.CodeAnalysis.Analyzers" Version="3.3.3">
             <PrivateAssets>all</PrivateAssets>
             <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
         </PackageReference>
-        <!--<PackageReference Include="Microsoft.CodeAnalysis.Common" Version="3.10.0" PrivateAssets="all" />-->
         <PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.1.0" PrivateAssets="all" />
     </ItemGroup>
 
-    <ItemGroup>
+    <!--<ItemGroup>
         <ProjectCapability Include="DynamicDependentFile" />
         <ProjectCapability Include="DynamicFileNesting" />
-    </ItemGroup>
+    </ItemGroup>-->
 
     <ItemGroup>
-        <Compile Update="ProxyClassesGenerator.*.cs">
+        <Compile Update="ProxyClassesGenerator.AutoMapper.cs">
             <DependentUpon>ProxyClassesGenerator.cs</DependentUpon>
         </Compile>
     </ItemGroup>
 
     <ItemGroup>
-      <None Remove="bin\Release\netstandard2.0\\ProxyInterfaceSourceGenerator.dll" />
+        <None Remove="bin\Release\netstandard2.0\\ProxyInterfaceSourceGenerator.dll" />
     </ItemGroup>
 
     <ItemGroup>