diff --git a/src/CodeGenHelpers/DelegateBuilder.cs b/src/CodeGenHelpers/DelegateBuilder.cs
index e5862ae..b9f662c 100644
--- a/src/CodeGenHelpers/DelegateBuilder.cs
+++ b/src/CodeGenHelpers/DelegateBuilder.cs
@@ -6,6 +6,7 @@
 
 namespace CodeGenHelpers;
 
+#nullable enable
 public sealed class DelegateBuilder : BuilderBase<DelegateBuilder>, IParameterized<DelegateBuilder>
 {
     private ParameterDocumentationComment? _xmlDoc;
diff --git a/src/CodeGenHelpers/Extensions/CodeHelpersGeneratorExtensions.cs b/src/CodeGenHelpers/Extensions/CodeHelpersGeneratorExtensions.cs
index c037a35..11cc940 100644
--- a/src/CodeGenHelpers/Extensions/CodeHelpersGeneratorExtensions.cs
+++ b/src/CodeGenHelpers/Extensions/CodeHelpersGeneratorExtensions.cs
@@ -6,6 +6,7 @@
 
 namespace Microsoft.CodeAnalysis;
 
+#nullable enable
 public static class CodeHelpersGeneratorExtensions
 {
     /// <summary>
diff --git a/src/CodeGenHelpers/Extensions/RoslynExtensions.cs b/src/CodeGenHelpers/Extensions/RoslynExtensions.cs
index 2b531ad..ba569f3 100644
--- a/src/CodeGenHelpers/Extensions/RoslynExtensions.cs
+++ b/src/CodeGenHelpers/Extensions/RoslynExtensions.cs
@@ -5,6 +5,7 @@
 
 namespace AvantiPoint.CodeGenHelpers.Extensions;
 
+#nullable enable
 public static class RoslynExtensions
 {
     /// <summary>
diff --git a/src/CodeGenHelpers/Extensions/SymbolExtensions.cs b/src/CodeGenHelpers/Extensions/SymbolExtensions.cs
index ceadbbf..e9e07c1 100644
--- a/src/CodeGenHelpers/Extensions/SymbolExtensions.cs
+++ b/src/CodeGenHelpers/Extensions/SymbolExtensions.cs
@@ -5,6 +5,7 @@
 
 namespace CodeGenHelpers.Extensions;
 
+#nullable enable
 public static class SymbolExtensions
 {
     public static string GetQualifiedTypeName(this ITypeSymbol typeSymbol)