diff --git a/Material.Icons/MaterialIconDataProvider.Declaration.cs b/Material.Icons/MaterialIconDataProvider.Declaration.cs
index 1a4c342..438b1ea 100644
--- a/Material.Icons/MaterialIconDataProvider.Declaration.cs
+++ b/Material.Icons/MaterialIconDataProvider.Declaration.cs
@@ -1,3 +1,5 @@
+using System;
+
 namespace Material.Icons;
 
 /// ******************************************
@@ -7,16 +9,24 @@ namespace Material.Icons;
 /// Allows retrieving data for icons
 /// </summary>
 public partial class MaterialIconDataProvider {
-    private static MaterialIconDataProvider? _instance;
+    private static MaterialIconDataProvider _instance = new();
+
     /// <summary>
-    /// Gets the singleton instance of this provider
+    /// Gets or sets the singleton instance of this provider
     /// </summary>
-    public static MaterialIconDataProvider Instance => _instance ??= new MaterialIconDataProvider();
+    public static MaterialIconDataProvider Instance {
+        get => _instance;
+        set {
+            _instance = value ?? throw new ArgumentNullException(nameof(value));
+        }
+    }
+
     /// <summary>
     /// Gets the data for the specified icon using the <see cref="Instance"/>
     /// </summary>
     /// <param name="kind">The icon kind</param>
     /// <returns>SVG path for target icon kind</returns>
+
     public static string GetData(MaterialIconKind kind) => Instance.ProvideData(kind);
     /// <summary>
     /// Provides the data for the specified icon kind
diff --git a/build/Generators/MaterialIconDataDeclarationGenerator.cs b/build/Generators/MaterialIconDataDeclarationGenerator.cs
index f132fab..4833bb1 100644
--- a/build/Generators/MaterialIconDataDeclarationGenerator.cs
+++ b/build/Generators/MaterialIconDataDeclarationGenerator.cs
@@ -9,8 +9,10 @@ public class MaterialIconDataDeclarationGenerator {
     public static void Write(AbsolutePath destinationPath) {
         var path = destinationPath / "MaterialIconDataProvider.Declaration.cs";
         Log.Information("Writing declaration for material icons data to {Path}", path);
-
+        
         var stringBuilder = new StringBuilder();
+        stringBuilder.AppendLine("using System;");
+        stringBuilder.AppendLine("");
         stringBuilder.AppendLine("namespace Material.Icons;");
         stringBuilder.AppendLine("");
         stringBuilder.AppendLine("/// ******************************************");
@@ -20,16 +22,24 @@ public static void Write(AbsolutePath destinationPath) {
         stringBuilder.AppendLine("/// Allows retrieving data for icons");
         stringBuilder.AppendLine("/// </summary>");
         stringBuilder.AppendLine("public partial class MaterialIconDataProvider {");
-        stringBuilder.AppendLine("    private static MaterialIconDataProvider? _instance;");
+        stringBuilder.AppendLine("    private static MaterialIconDataProvider _instance = new();");
+        stringBuilder.AppendLine("");
         stringBuilder.AppendLine("    /// <summary>");
-        stringBuilder.AppendLine("    /// Gets the singleton instance of this provider");
+        stringBuilder.AppendLine("    /// Gets or sets the singleton instance of this provider");
         stringBuilder.AppendLine("    /// </summary>");
-        stringBuilder.AppendLine("    public static MaterialIconDataProvider Instance => _instance ??= new MaterialIconDataProvider();");
+        stringBuilder.AppendLine("    public static MaterialIconDataProvider Instance {");
+        stringBuilder.AppendLine("        get => _instance;");
+        stringBuilder.AppendLine("        set {");
+        stringBuilder.AppendLine("            _instance = value ?? throw new ArgumentNullException(nameof(value));");
+        stringBuilder.AppendLine("        }");
+        stringBuilder.AppendLine("    }");
+        stringBuilder.AppendLine("");
         stringBuilder.AppendLine("    /// <summary>");
         stringBuilder.AppendLine("    /// Gets the data for the specified icon using the <see cref=\"Instance\"/>");
         stringBuilder.AppendLine("    /// </summary>");
         stringBuilder.AppendLine("    /// <param name=\"kind\">The icon kind</param>");
         stringBuilder.AppendLine("    /// <returns>SVG path for target icon kind</returns>");
+        stringBuilder.AppendLine("");
         stringBuilder.AppendLine("    public static string GetData(MaterialIconKind kind) => Instance.ProvideData(kind);");
         stringBuilder.AppendLine("    /// <summary>");
         stringBuilder.AppendLine("    /// Provides the data for the specified icon kind");