diff --git a/README.md b/README.md
index bdeca4d..ddcbdbb 100644
--- a/README.md
+++ b/README.md
@@ -24,8 +24,8 @@ IServiceCollection serviceCollection;
 
 // you may need to add these dependencies
 serviceCollection.AddMemoryCache();
-using Microsoft.Extensions.Internal;
-serviceCollection.TryAddSingleton<ISystemClock, SystemClock>();
+using System;
+serviceCollection.TryAddSingleton<TimeProvider>(TimeProvider.System);
 
 // configure AppStoreConnect services
 serviceCollection.AddAppleAppStoreConnect(optionsBuilder => optionsBuilder
diff --git a/src/Apple.AppStoreConnect/Apple.AppStoreConnect.csproj b/src/Apple.AppStoreConnect/Apple.AppStoreConnect.csproj
index 38e7dd8..ca85192 100644
--- a/src/Apple.AppStoreConnect/Apple.AppStoreConnect.csproj
+++ b/src/Apple.AppStoreConnect/Apple.AppStoreConnect.csproj
@@ -32,6 +32,7 @@
 
   <ItemGroup Condition=" '$(TargetFramework)' == 'net7.0' ">
     <PackageReference Include="H.NSwag.Generator" Version="14.0.7.76" PrivateAssets="All" />
+    <PackageReference Include="Microsoft.Bcl.TimeProvider" Version="8.0.1" />
     <PackageReference Include="Microsoft.Extensions.Caching.Abstractions" Version="7.0.0" />
     <PackageReference Include="Microsoft.Extensions.Http" Version="7.0.0" />
     <PackageReference Include="Microsoft.Extensions.Options" Version="7.0.1" />
@@ -41,6 +42,7 @@
 
   <ItemGroup Condition=" '$(TargetFramework)' == 'net8.0' ">
     <PackageReference Include="H.NSwag.Generator" Version="14.0.7.76" PrivateAssets="All" />
+    <PackageReference Include="Microsoft.Bcl.TimeProvider" Version="8.0.1" />
     <PackageReference Include="Microsoft.Extensions.Caching.Abstractions" Version="8.0.0" />
     <PackageReference Include="Microsoft.Extensions.Http" Version="8.0.0" />
     <PackageReference Include="Microsoft.Extensions.Options" Version="8.0.2" />
diff --git a/src/Apple.AppStoreConnect/DefaultJwtGenerator.cs b/src/Apple.AppStoreConnect/DefaultJwtGenerator.cs
index 97014ef..86b6bf0 100644
--- a/src/Apple.AppStoreConnect/DefaultJwtGenerator.cs
+++ b/src/Apple.AppStoreConnect/DefaultJwtGenerator.cs
@@ -1,6 +1,5 @@
 using Apple.AppStoreConnect.Interfaces;
 using Microsoft.Extensions.Caching.Memory;
-using Microsoft.Extensions.Internal;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
 using Microsoft.IdentityModel.Tokens;
@@ -14,19 +13,19 @@ namespace Apple.AppStoreConnect;
 public partial class DefaultJwtGenerator : IJwtGenerator
 {
     private readonly IMemoryCache _cache;
-    private readonly ISystemClock _clock;
+    private readonly TimeProvider _timeProvider;
     private readonly IOptions<AppleAuthenticationOptions> _appleAuthenticationOptions;
     private readonly ILogger _logger;
 
     public DefaultJwtGenerator(
         IMemoryCache cache,
-        ISystemClock clock,
+        TimeProvider timeProvider,
         IOptions<AppleAuthenticationOptions> appleAuthenticationOptions,
         ILogger<DefaultJwtGenerator> logger
     )
     {
         _cache = cache;
-        _clock = clock;
+        _timeProvider = timeProvider;
         _appleAuthenticationOptions = appleAuthenticationOptions;
         _logger = logger;
     }
@@ -78,7 +77,7 @@ AppleAuthenticationOptions options
         AppleAuthenticationOptions appleAuthenticationOptions, CancellationToken cancellationToken
     )
     {
-        var now = _clock.UtcNow;
+        var now = _timeProvider.GetUtcNow();
         var expiresAt = now.Add(appleAuthenticationOptions.JwtExpiresAfter);
 
         Log.GeneratingNewJwtToken(_logger, appleAuthenticationOptions.KeyId, expiresAt);
diff --git a/src/Test.Apple.AppStoreConnect/DefaultJwtGeneratorTest.cs b/src/Test.Apple.AppStoreConnect/DefaultJwtGeneratorTest.cs
index 001283f..33bde17 100644
--- a/src/Test.Apple.AppStoreConnect/DefaultJwtGeneratorTest.cs
+++ b/src/Test.Apple.AppStoreConnect/DefaultJwtGeneratorTest.cs
@@ -3,9 +3,9 @@
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.DependencyInjection.Extensions;
 using Microsoft.Extensions.FileProviders;
-using Microsoft.Extensions.Internal;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
+using Microsoft.Extensions.Time.Testing;
 using System;
 using System.IO;
 using System.Threading.Tasks;
@@ -43,7 +43,7 @@ public async Task GenerateJwtTokenWorks()
                 .AddConsole()
                 .AddDebug()
             )
-            .AddSingleton<ISystemClock, SystemClock>();
+            .AddSingleton<TimeProvider, FakeTimeProvider>();
 
         serviceCollection.TryAddEnumerable(ServiceDescriptor
             .Singleton<IPostConfigureOptions<AppleAuthenticationOptions>, AppleAuthenticationPostConfigure>()
@@ -90,7 +90,8 @@ public async Task TwoGenerateJwtTokenWorks(int delay)
                 .AddConsole()
                 .AddDebug()
             )
-            .AddSingleton<ISystemClock, SystemClock>();
+            .AddSingleton<FakeTimeProvider>()
+            .AddSingleton<TimeProvider>(s => s.GetRequiredService<FakeTimeProvider>());
 
         serviceCollection.TryAddEnumerable(ServiceDescriptor
             .Singleton<IPostConfigureOptions<AppleAuthenticationOptions>, AppleAuthenticationPostConfigure>()
diff --git a/src/Test.Apple.AppStoreConnect/Test.Apple.AppStoreConnect.csproj b/src/Test.Apple.AppStoreConnect/Test.Apple.AppStoreConnect.csproj
index 1b6a8e6..054eaaf 100644
--- a/src/Test.Apple.AppStoreConnect/Test.Apple.AppStoreConnect.csproj
+++ b/src/Test.Apple.AppStoreConnect/Test.Apple.AppStoreConnect.csproj
@@ -28,6 +28,7 @@
   </ItemGroup>
 
   <ItemGroup Condition=" '$(TargetFramework)' == 'net7.0' ">
+    <PackageReference Include="Microsoft.Extensions.TimeProvider.Testing" Version="8.4.0" />
     <PackageReference Include="Microsoft.Extensions.Caching.Memory" Version="8.0.0" />
     <PackageReference Include="Microsoft.Extensions.FileProviders.Embedded" Version="8.0.2" />
     <PackageReference Include="Microsoft.Extensions.FileProviders.Physical" Version="8.0.0" />
@@ -35,6 +36,7 @@
   </ItemGroup>
 
   <ItemGroup Condition=" '$(TargetFramework)' == 'net8.0' ">
+    <PackageReference Include="Microsoft.Extensions.TimeProvider.Testing" Version="8.4.0" />
     <PackageReference Include="Microsoft.Extensions.Caching.Memory" Version="8.0.0" />
     <PackageReference Include="Microsoft.Extensions.FileProviders.Embedded" Version="8.0.4" />
     <PackageReference Include="Microsoft.Extensions.FileProviders.Physical" Version="8.0.0" />