diff --git a/src/Blazored.LocalStorage.TestExtensions/BUnitLocalStorageTestExtensions.cs b/src/Blazored.LocalStorage.TestExtensions/BUnitLocalStorageTestExtensions.cs
index 1018400..5f0c19d 100644
--- a/src/Blazored.LocalStorage.TestExtensions/BUnitLocalStorageTestExtensions.cs
+++ b/src/Blazored.LocalStorage.TestExtensions/BUnitLocalStorageTestExtensions.cs
@@ -15,7 +15,7 @@ public static class BUnitLocalStorageTestExtensions
         public static ILocalStorageService AddBlazoredLocalStorage(this TestContextBase context)
             => AddBlazoredLocalStorage(context, null);
 
-        public static ILocalStorageService AddBlazoredLocalStorage(this TestContextBase context, Action<LocalStorageOptions> configure)
+        public static ILocalStorageService AddBlazoredLocalStorage(this TestContextBase context, Action<LocalStorageOptions>? configure)
         {
             if (context is null)
                 throw new ArgumentNullException(nameof(context));
diff --git a/src/Blazored.LocalStorage.TestExtensions/Blazored.LocalStorage.TestExtensions.csproj b/src/Blazored.LocalStorage.TestExtensions/Blazored.LocalStorage.TestExtensions.csproj
index a907a80..c8ed1fc 100644
--- a/src/Blazored.LocalStorage.TestExtensions/Blazored.LocalStorage.TestExtensions.csproj
+++ b/src/Blazored.LocalStorage.TestExtensions/Blazored.LocalStorage.TestExtensions.csproj
@@ -2,6 +2,7 @@
 
   <PropertyGroup>
     <TargetFrameworks>net6.0;net7.0</TargetFrameworks>
+    <Nullable>enable</Nullable>
 
     <Authors>Chris Sainty</Authors>
     <Company>Chris Sainty</Company>
diff --git a/src/Blazored.LocalStorage.TestExtensions/InMemoryStorageProvider.cs b/src/Blazored.LocalStorage.TestExtensions/InMemoryStorageProvider.cs
index a09b688..12c2bc6 100644
--- a/src/Blazored.LocalStorage.TestExtensions/InMemoryStorageProvider.cs
+++ b/src/Blazored.LocalStorage.TestExtensions/InMemoryStorageProvider.cs
@@ -7,7 +7,7 @@ namespace Blazored.LocalStorage.TestExtensions
 {
     internal class InMemoryStorageProvider : IStorageProvider
     {
-        private readonly Dictionary<string, string> _dataStore = new Dictionary<string, string>();
+        private readonly Dictionary<string, string> _dataStore = new();
 
         public void Clear()
             => _dataStore.Clear();
@@ -22,34 +22,31 @@ public bool ContainKey(string key)
             => _dataStore.ContainsKey(key);
 
         public ValueTask<bool> ContainKeyAsync(string key, CancellationToken cancellationToken = default)
-            => new ValueTask<bool>(ContainKey(key));
+            => new(ContainKey(key));
 
-        public string GetItem(string key)
+        public string? GetItem(string key)
             => _dataStore.ContainsKey(key) ? _dataStore[key] : default;
 
-        public ValueTask<string> GetItemAsync(string key, CancellationToken cancellationToken = default)
-            => new ValueTask<string>(GetItem(key));
+        public ValueTask<string?> GetItemAsync(string key, CancellationToken cancellationToken = default) 
+            => new(GetItem(key));
 
-        public string Key(int index)
+        public string? Key(int index)
             => index > _dataStore.Count - 1 ? default : _dataStore.ElementAt(index).Key;
 
-        public ValueTask<string> KeyAsync(int index, CancellationToken cancellationToken = default)
-            => new ValueTask<string>(Key(index));
+        public ValueTask<string?> KeyAsync(int index, CancellationToken cancellationToken = default) 
+            => new(Key(index));
 
-        public IEnumerable<string> Keys()
-        {
-            return _dataStore.Keys.ToList();
-        }
-
-        public ValueTask<IEnumerable<string>> KeysAsync(CancellationToken cancellationToken = default)
-            => new ValueTask<IEnumerable<string>>(_dataStore.Keys.ToList());
+        public IEnumerable<string> Keys() 
+            => _dataStore.Keys.ToList();
 
+        public ValueTask<IEnumerable<string>> KeysAsync(CancellationToken cancellationToken = default) 
+            => new(_dataStore.Keys.ToList());
 
         public int Length()
             => _dataStore.Count;
 
         public ValueTask<int> LengthAsync(CancellationToken cancellationToken = default)
-            => new ValueTask<int>(Length());
+            => new(Length());
 
         public void RemoveItem(string key)
             => _dataStore.Remove(key);
diff --git a/src/Blazored.LocalStorage/Blazored.LocalStorage.csproj b/src/Blazored.LocalStorage/Blazored.LocalStorage.csproj
index 7dd4b2d..35c6f08 100644
--- a/src/Blazored.LocalStorage/Blazored.LocalStorage.csproj
+++ b/src/Blazored.LocalStorage/Blazored.LocalStorage.csproj
@@ -2,6 +2,7 @@
 
   <PropertyGroup>
     <TargetFrameworks>net6.0;net7.0;net8.0</TargetFrameworks>
+    <Nullable>enable</Nullable>
 
     <Authors>Chris Sainty</Authors>
     <Company>Chris Sainty</Company>
diff --git a/src/Blazored.LocalStorage/BrowserStorageProvider.cs b/src/Blazored.LocalStorage/BrowserStorageProvider.cs
index f5ce6f0..0d98f9b 100644
--- a/src/Blazored.LocalStorage/BrowserStorageProvider.cs
+++ b/src/Blazored.LocalStorage/BrowserStorageProvider.cs
@@ -1,6 +1,7 @@
 using Microsoft.JSInterop;
 using System;
 using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
 using System.Threading;
 using System.Threading.Tasks;
 using Blazored.LocalStorage.Exceptions;
@@ -12,7 +13,7 @@ internal class BrowserStorageProvider : IStorageProvider
         private const string StorageNotAvailableMessage = "Unable to access the browser storage. This is most likely due to the browser settings.";
         
         private readonly IJSRuntime _jSRuntime;
-        private readonly IJSInProcessRuntime _jSInProcessRuntime;
+        private readonly IJSInProcessRuntime? _jSInProcessRuntime;
 
         public BrowserStorageProvider(IJSRuntime jSRuntime)
         {
@@ -37,11 +38,11 @@ public async ValueTask ClearAsync(CancellationToken cancellationToken = default)
             }
         }
 
-        public async ValueTask<string> GetItemAsync(string key, CancellationToken cancellationToken = default)
+        public async ValueTask<string?> GetItemAsync(string key, CancellationToken cancellationToken = default)
         {
             try
             {
-                return await _jSRuntime.InvokeAsync<string>("localStorage.getItem", cancellationToken, key);
+                return await _jSRuntime.InvokeAsync<string?>("localStorage.getItem", cancellationToken, key);
             }
             catch (Exception exception)
             {
@@ -54,11 +55,11 @@ public async ValueTask<string> GetItemAsync(string key, CancellationToken cancel
             }
         }
 
-        public async ValueTask<string> KeyAsync(int index, CancellationToken cancellationToken = default)
+        public async ValueTask<string?> KeyAsync(int index, CancellationToken cancellationToken = default)
         {
             try
             {
-                return await _jSRuntime.InvokeAsync<string>("localStorage.key", cancellationToken, index);
+                return await _jSRuntime.InvokeAsync<string?>("localStorage.key", cancellationToken, index);
             }
             catch (Exception exception)
             {
@@ -175,7 +176,7 @@ public async ValueTask RemoveItemsAsync(IEnumerable<string> keys, CancellationTo
                 throw;
             }
         }
-
+        
         public void Clear()
         {
             CheckForInProcessRuntime();
@@ -341,6 +342,7 @@ public IEnumerable<string> Keys()
             }
         }
 
+        [MemberNotNull(nameof(_jSInProcessRuntime))]
         private void CheckForInProcessRuntime()
         {
             if (_jSInProcessRuntime == null)
diff --git a/src/Blazored.LocalStorage/ChangedEventArgs.cs b/src/Blazored.LocalStorage/ChangedEventArgs.cs
index 1f55deb..85562f8 100644
--- a/src/Blazored.LocalStorage/ChangedEventArgs.cs
+++ b/src/Blazored.LocalStorage/ChangedEventArgs.cs
@@ -5,8 +5,8 @@ namespace Blazored.LocalStorage
     [ExcludeFromCodeCoverage]
     public class ChangedEventArgs
     {
-        public string Key { get; set; }
-        public object OldValue { get; set; }
-        public object NewValue { get; set; }
+        public string Key { get; set; } = null!; // Since .NET 6 is supported, `required` is not available yet
+        public object? OldValue { get; set; }
+        public object? NewValue { get; set; }
     }
-}
\ No newline at end of file
+}
diff --git a/src/Blazored.LocalStorage/ILocalStorageService.cs b/src/Blazored.LocalStorage/ILocalStorageService.cs
index cbdd4c7..7f92b5b 100644
--- a/src/Blazored.LocalStorage/ILocalStorageService.cs
+++ b/src/Blazored.LocalStorage/ILocalStorageService.cs
@@ -22,7 +22,7 @@ public interface ILocalStorageService
         /// (<see cref="JSRuntime.DefaultAsyncTimeout"/>) from being applied.
         /// </param>
         /// <returns>A <see cref="ValueTask"/> representing the completion of the operation.</returns>
-        ValueTask<T> GetItemAsync<T>(string key, CancellationToken cancellationToken = default);
+        ValueTask<T?> GetItemAsync<T>(string key, CancellationToken cancellationToken = default);
 
         /// <summary>
         /// Retrieve the specified data from local storage as a <see cref="string"/>.
@@ -33,7 +33,7 @@ public interface ILocalStorageService
         /// (<see cref="JSRuntime.DefaultAsyncTimeout"/>) from being applied.
         /// </param>
         /// <returns>A <see cref="ValueTask"/> representing the completion of the operation.</returns>
-        ValueTask<string> GetItemAsStringAsync(string key, CancellationToken cancellationToken = default);
+        ValueTask<string?> GetItemAsStringAsync(string key, CancellationToken cancellationToken = default);
 
         /// <summary>
         /// Return the name of the key at the specified <paramref name="index"/>.
@@ -44,7 +44,7 @@ public interface ILocalStorageService
         /// (<see cref="JSRuntime.DefaultAsyncTimeout"/>) from being applied.
         /// </param>
         /// <returns>A <see cref="ValueTask"/> representing the completion of the operation.</returns>
-        ValueTask<string> KeyAsync(int index, CancellationToken cancellationToken = default);
+        ValueTask<string?> KeyAsync(int index, CancellationToken cancellationToken = default);
 
         /// <summary>
         /// Returns a collection of strings representing the names of the keys in the local storage.
diff --git a/src/Blazored.LocalStorage/IStorageProvider.cs b/src/Blazored.LocalStorage/IStorageProvider.cs
index d7c181a..cf69df9 100644
--- a/src/Blazored.LocalStorage/IStorageProvider.cs
+++ b/src/Blazored.LocalStorage/IStorageProvider.cs
@@ -10,10 +10,10 @@ internal interface IStorageProvider
         ValueTask ClearAsync(CancellationToken cancellationToken = default);
         bool ContainKey(string key);
         ValueTask<bool> ContainKeyAsync(string key, CancellationToken cancellationToken = default);
-        string GetItem(string key);
-        ValueTask<string> GetItemAsync(string key, CancellationToken cancellationToken = default);
-        string Key(int index);
-        ValueTask<string> KeyAsync(int index, CancellationToken cancellationToken = default);
+        string? GetItem(string key);
+        ValueTask<string?> GetItemAsync(string key, CancellationToken cancellationToken = default);
+        string? Key(int index);
+        ValueTask<string?> KeyAsync(int index, CancellationToken cancellationToken = default);
         IEnumerable<string> Keys();
         ValueTask<IEnumerable<string>> KeysAsync(CancellationToken cancellationToken = default);
         int Length();
diff --git a/src/Blazored.LocalStorage/ISyncLocalStorageService.cs b/src/Blazored.LocalStorage/ISyncLocalStorageService.cs
index ac886bb..d29a653 100644
--- a/src/Blazored.LocalStorage/ISyncLocalStorageService.cs
+++ b/src/Blazored.LocalStorage/ISyncLocalStorageService.cs
@@ -15,21 +15,21 @@ public interface ISyncLocalStorageService
         /// </summary>
         /// <param name="key">A <see cref="string"/> value specifying the name of the local storage slot to use</param>
         /// <returns>The data from the specified <paramref name="key"/> as a <typeparamref name="T"/></returns>
-        T GetItem<T>(string key);
+        T? GetItem<T>(string key);
 
         /// <summary>
         /// Retrieve the specified data from local storage as a <see cref="string"/>.
         /// </summary>
         /// <param name="key">A <see cref="string"/> value specifying the name of the storage slot to use</param>
         /// <returns>The data associated with the specified <paramref name="key"/> as a <see cref="string"/></returns>
-        string GetItemAsString(string key);
+        string? GetItemAsString(string key);
 
         /// <summary>
         /// Return the name of the key at the specified <paramref name="index"/>.
         /// </summary>
         /// <param name="index"></param>
         /// <returns>The name of the key at the specified <paramref name="index"/></returns>
-        string Key(int index);
+        string? Key(int index);
 
         /// <summary>
         /// Checks if the <paramref name="key"/> exists in local storage, but does not check its value.
diff --git a/src/Blazored.LocalStorage/LocalStorageService.cs b/src/Blazored.LocalStorage/LocalStorageService.cs
index 4114374..c61cb35 100644
--- a/src/Blazored.LocalStorage/LocalStorageService.cs
+++ b/src/Blazored.LocalStorage/LocalStorageService.cs
@@ -52,7 +52,7 @@ public async ValueTask SetItemAsStringAsync(string key, string data, Cancellatio
             RaiseOnChanged(key, e.OldValue, data);
         }
 
-        public async ValueTask<T> GetItemAsync<T>(string key, CancellationToken cancellationToken = default)
+        public async ValueTask<T?> GetItemAsync<T>(string key, CancellationToken cancellationToken = default)
         {
             if (string.IsNullOrWhiteSpace(key))
                 throw new ArgumentNullException(nameof(key));
@@ -74,7 +74,7 @@ public async ValueTask<T> GetItemAsync<T>(string key, CancellationToken cancella
             }
         }
 
-        public ValueTask<string> GetItemAsStringAsync(string key, CancellationToken cancellationToken = default)
+        public ValueTask<string?> GetItemAsStringAsync(string key, CancellationToken cancellationToken = default)
         {
             if (string.IsNullOrWhiteSpace(key))
                 throw new ArgumentNullException(nameof(key));
@@ -96,7 +96,7 @@ public ValueTask ClearAsync(CancellationToken cancellationToken = default)
         public ValueTask<int> LengthAsync(CancellationToken cancellationToken = default)
             => _storageProvider.LengthAsync(cancellationToken);
 
-        public ValueTask<string> KeyAsync(int index, CancellationToken cancellationToken = default)
+        public ValueTask<string?> KeyAsync(int index, CancellationToken cancellationToken = default)
             => _storageProvider.KeyAsync(index, cancellationToken);
 
         public ValueTask<IEnumerable<string>> KeysAsync(CancellationToken cancellationToken = default)
@@ -134,8 +134,7 @@ public void SetItemAsString(string key, string data)
             if (string.IsNullOrWhiteSpace(key))
                 throw new ArgumentNullException(nameof(key));
 
-            if (data is null)
-                throw new ArgumentNullException(nameof(data));
+            ArgumentNullException.ThrowIfNull(data);
 
             var e = RaiseOnChangingSync(key, data);
 
@@ -147,7 +146,7 @@ public void SetItemAsString(string key, string data)
             RaiseOnChanged(key, e.OldValue, data);
         }
 
-        public T GetItem<T>(string key)
+        public T? GetItem<T>(string key)
         {
             if (string.IsNullOrWhiteSpace(key))
                 throw new ArgumentNullException(nameof(key));
@@ -169,7 +168,7 @@ public T GetItem<T>(string key)
             }
         }
 
-        public string GetItemAsString(string key)
+        public string? GetItemAsString(string key)
         {
             if (string.IsNullOrWhiteSpace(key))
                 throw new ArgumentNullException(nameof(key));
@@ -202,14 +201,14 @@ public void Clear()
         public int Length()
             => _storageProvider.Length();
 
-        public string Key(int index)
+        public string? Key(int index)
             => _storageProvider.Key(index);
 
         public bool ContainKey(string key)
             => _storageProvider.ContainKey(key);
 
-        public event EventHandler<ChangingEventArgs> Changing;
-        private async Task<ChangingEventArgs> RaiseOnChangingAsync(string key, object data)
+        public event EventHandler<ChangingEventArgs>? Changing;
+        private async Task<ChangingEventArgs> RaiseOnChangingAsync(string key, object? data)
         {
             var e = new ChangingEventArgs
             {
@@ -223,7 +222,7 @@ private async Task<ChangingEventArgs> RaiseOnChangingAsync(string key, object da
             return e;
         }
 
-        private ChangingEventArgs RaiseOnChangingSync(string key, object data)
+        private ChangingEventArgs RaiseOnChangingSync(string key, object? data)
         {
             var e = new ChangingEventArgs
             {
@@ -237,7 +236,7 @@ private ChangingEventArgs RaiseOnChangingSync(string key, object data)
             return e;
         }
 
-        private async Task<T> GetItemInternalAsync<T>(string key, CancellationToken cancellationToken = default)
+        private async Task<T?> GetItemInternalAsync<T>(string key, CancellationToken cancellationToken = default)
         {
             if (string.IsNullOrEmpty(key))
                 throw new ArgumentNullException(nameof(key));
@@ -256,7 +255,7 @@ private async Task<T> GetItemInternalAsync<T>(string key, CancellationToken canc
             }
         }
 
-        private object GetItemInternal(string key)
+        private object? GetItemInternal(string key)
         {
             if (string.IsNullOrEmpty(key))
                 throw new ArgumentNullException(nameof(key));
@@ -276,8 +275,8 @@ private object GetItemInternal(string key)
             }
         }
 
-        public event EventHandler<ChangedEventArgs> Changed;
-        private void RaiseOnChanged(string key, object oldValue, object data)
+        public event EventHandler<ChangedEventArgs>? Changed;
+        private void RaiseOnChanged(string key, object? oldValue, object? data)
         {
             var e = new ChangedEventArgs
             {
diff --git a/src/Blazored.LocalStorage/Serialization/IJsonSerializer.cs b/src/Blazored.LocalStorage/Serialization/IJsonSerializer.cs
index a1fdc9b..f1689ba 100644
--- a/src/Blazored.LocalStorage/Serialization/IJsonSerializer.cs
+++ b/src/Blazored.LocalStorage/Serialization/IJsonSerializer.cs
@@ -3,6 +3,6 @@ namespace Blazored.LocalStorage.Serialization
     public interface IJsonSerializer
     {
         string Serialize<T>(T obj);
-        T Deserialize<T>(string text);
+        T? Deserialize<T>(string text);
     }
 }
diff --git a/src/Blazored.LocalStorage/Serialization/SystemTextJsonSerializer.cs b/src/Blazored.LocalStorage/Serialization/SystemTextJsonSerializer.cs
index 3bc7011..9db26e1 100644
--- a/src/Blazored.LocalStorage/Serialization/SystemTextJsonSerializer.cs
+++ b/src/Blazored.LocalStorage/Serialization/SystemTextJsonSerializer.cs
@@ -13,12 +13,12 @@ public SystemTextJsonSerializer(IOptions<LocalStorageOptions> options)
             _options = options.Value.JsonSerializerOptions;
         }
 
-        public SystemTextJsonSerializer(LocalStorageOptions localStorageOptions)
-        {
-            _options = localStorageOptions.JsonSerializerOptions;
+        public SystemTextJsonSerializer(LocalStorageOptions localStorageOptions)
+        {
+            _options = localStorageOptions.JsonSerializerOptions;
         }
 
-        public T Deserialize<T>(string data) 
+        public T? Deserialize<T>(string data) 
             => JsonSerializer.Deserialize<T>(data, _options);
 
         public string Serialize<T>(T data)
diff --git a/src/Blazored.LocalStorage/ServiceCollectionExtensions.cs b/src/Blazored.LocalStorage/ServiceCollectionExtensions.cs
index e59eb97..60c0342 100644
--- a/src/Blazored.LocalStorage/ServiceCollectionExtensions.cs
+++ b/src/Blazored.LocalStorage/ServiceCollectionExtensions.cs
@@ -16,7 +16,7 @@ public static class ServiceCollectionExtensions
         public static IServiceCollection AddBlazoredLocalStorage(this IServiceCollection services)
             => AddBlazoredLocalStorage(services, null);
 
-        public static IServiceCollection AddBlazoredLocalStorage(this IServiceCollection services, Action<LocalStorageOptions> configure)
+        public static IServiceCollection AddBlazoredLocalStorage(this IServiceCollection services, Action<LocalStorageOptions>? configure)
         {
             services.TryAddScoped<IJsonSerializer, SystemTextJsonSerializer>();
             services.TryAddScoped<IStorageProvider, BrowserStorageProvider>();
@@ -49,7 +49,7 @@ public static IServiceCollection AddBlazoredLocalStorageAsSingleton(this IServic
         /// <param name="services"></param>
         /// <param name="configure"></param>
         /// <returns></returns>
-        public static IServiceCollection AddBlazoredLocalStorageAsSingleton(this IServiceCollection services, Action<LocalStorageOptions> configure)
+        public static IServiceCollection AddBlazoredLocalStorageAsSingleton(this IServiceCollection services, Action<LocalStorageOptions>? configure)
         {
             services.TryAddSingleton<IJsonSerializer, SystemTextJsonSerializer>();
             services.TryAddSingleton<IStorageProvider, BrowserStorageProvider>();