diff --git a/build/Common.tests.props b/build/Common.tests.props
index 71b4578e..8a533a23 100644
--- a/build/Common.tests.props
+++ b/build/Common.tests.props
@@ -29,7 +29,7 @@
     </PackageReference>
     <PackageReference Include="FluentAssertions" Version="$(FluentAssertionsVer)" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="$(MicrosoftNETTestSdkPkgVer)" />
-    <PackageReference Include="Moq" Version="$(MoqVer)" />
+    <PackageReference Include="NSubstitute" Version="$(NSubstituteVer)" />
     <PackageReference Include="xunit" Version="$(XUnitPkgVer)" />
     <PackageReference Include="xunit.runner.visualstudio" Version="$(XUnitRunnerVisualStudioPkgVer)">
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
@@ -46,7 +46,7 @@
     <CoverletCollectorVer>[3.1.2]</CoverletCollectorVer>
     <FluentAssertionsVer>[6.7.0]</FluentAssertionsVer>
     <MicrosoftNETTestSdkPkgVer>[17.3.2]</MicrosoftNETTestSdkPkgVer>
-    <MoqVer>[4.18.2]</MoqVer>
+    <NSubstituteVer>[5.0.0]</NSubstituteVer>
     <XUnitRunnerVisualStudioPkgVer>[2.4.3,3.0)</XUnitRunnerVisualStudioPkgVer>
     <XUnitPkgVer>[2.4.1,3.0)</XUnitPkgVer>
   </PropertyGroup>
diff --git a/test/OpenFeature.Contrib.Providers.Flagd.Test/FlagdProviderTest.cs b/test/OpenFeature.Contrib.Providers.Flagd.Test/FlagdProviderTest.cs
index e1115505..caf3de18 100644
--- a/test/OpenFeature.Contrib.Providers.Flagd.Test/FlagdProviderTest.cs
+++ b/test/OpenFeature.Contrib.Providers.Flagd.Test/FlagdProviderTest.cs
@@ -1,5 +1,4 @@
 using Xunit;
-using Moq;
 using OpenFeature.Flagd.Grpc;
 using Grpc.Core;
 using Google.Protobuf.WellKnownTypes;
@@ -9,6 +8,7 @@
 using OpenFeature.Model;
 using System.Threading;
 using System;
+using NSubstitute;
 
 namespace OpenFeature.Contrib.Providers.Flagd.Test
 {
@@ -120,8 +120,10 @@ public void TestGetProviderWithConfig()
         [Fact]
         public void TestResolveBooleanValue()
         {
-            var resp = new ResolveBooleanResponse();
-            resp.Value = true;
+            var resp = new ResolveBooleanResponse
+            {
+                Value = true
+            };
 
             var grpcResp = new AsyncUnaryCall<ResolveBooleanResponse>(
                 System.Threading.Tasks.Task.FromResult(resp),
@@ -130,13 +132,13 @@ public void TestResolveBooleanValue()
                 () => new Grpc.Core.Metadata(),
                 () => { });
 
-            var mockGrpcClient = new Mock<Service.ServiceClient>();
-            mockGrpcClient
-                .Setup(m => m.ResolveBooleanAsync(
-                    It.IsAny<ResolveBooleanRequest>(), null, null, System.Threading.CancellationToken.None))
+            var substituteGrpcClient = Substitute.For<Service.ServiceClient>();
+            substituteGrpcClient
+                .ResolveBooleanAsync(
+                    Arg.Any<ResolveBooleanRequest>(), null, null, System.Threading.CancellationToken.None)
                 .Returns(grpcResp);
 
-            var flagdProvider = new FlagdProvider(mockGrpcClient.Object, new FlagdConfig());
+            var flagdProvider = new FlagdProvider(substituteGrpcClient, new FlagdConfig());
 
             // resolve with default set to false to make sure we return what the grpc server gives us
             var val = flagdProvider.ResolveBooleanValue("my-key", false, null);
@@ -147,8 +149,7 @@ public void TestResolveBooleanValue()
         [Fact]
         public void TestResolveStringValue()
         {
-            var resp = new ResolveStringResponse();
-            resp.Value = "my-value";
+            var resp = new ResolveStringResponse { Value = "my-value" };
 
             var grpcResp = new AsyncUnaryCall<ResolveStringResponse>(
                 System.Threading.Tasks.Task.FromResult(resp),
@@ -157,13 +158,13 @@ public void TestResolveStringValue()
                 () => new Grpc.Core.Metadata(),
                 () => { });
 
-            var mockGrpcClient = new Mock<Service.ServiceClient>();
-            mockGrpcClient
-                .Setup(m => m.ResolveStringAsync(
-                    It.IsAny<ResolveStringRequest>(), null, null, System.Threading.CancellationToken.None))
+            var subGrpcClient = Substitute.For<Service.ServiceClient>();
+
+            subGrpcClient.ResolveStringAsync(
+                    Arg.Any<ResolveStringRequest>(), null, null, System.Threading.CancellationToken.None)
                 .Returns(grpcResp);
 
-            var flagdProvider = new FlagdProvider(mockGrpcClient.Object, new FlagdConfig());
+            var flagdProvider = new FlagdProvider(subGrpcClient, new FlagdConfig());
 
             var val = flagdProvider.ResolveStringValue("my-key", "", null);
 
@@ -173,8 +174,10 @@ public void TestResolveStringValue()
         [Fact]
         public void TestResolveIntegerValue()
         {
-            var resp = new ResolveIntResponse();
-            resp.Value = 10;
+            var resp = new ResolveIntResponse
+            {
+                Value = 10
+            };
 
             var grpcResp = new AsyncUnaryCall<ResolveIntResponse>(
                 System.Threading.Tasks.Task.FromResult(resp),
@@ -183,13 +186,11 @@ public void TestResolveIntegerValue()
                 () => new Grpc.Core.Metadata(),
                 () => { });
 
-            var mockGrpcClient = new Mock<Service.ServiceClient>();
-            mockGrpcClient
-                .Setup(m => m.ResolveIntAsync(
-                    It.IsAny<ResolveIntRequest>(), null, null, System.Threading.CancellationToken.None))
+            var subGrpcClient = Substitute.For<Service.ServiceClient>();
+            subGrpcClient.ResolveIntAsync(Arg.Any<ResolveIntRequest>(), null, null, System.Threading.CancellationToken.None)
                 .Returns(grpcResp);
 
-            var flagdProvider = new FlagdProvider(mockGrpcClient.Object, new FlagdConfig());
+            var flagdProvider = new FlagdProvider(subGrpcClient, new FlagdConfig());
 
             var val = flagdProvider.ResolveIntegerValue("my-key", 0, null);
 
@@ -199,8 +200,10 @@ public void TestResolveIntegerValue()
         [Fact]
         public void TestResolveDoubleValue()
         {
-            var resp = new ResolveFloatResponse();
-            resp.Value = 10.0;
+            var resp = new ResolveFloatResponse
+            {
+                Value = 10.0
+            };
 
             var grpcResp = new AsyncUnaryCall<ResolveFloatResponse>(
                 System.Threading.Tasks.Task.FromResult(resp),
@@ -209,13 +212,11 @@ public void TestResolveDoubleValue()
                 () => new Grpc.Core.Metadata(),
                 () => { });
 
-            var mockGrpcClient = new Mock<Service.ServiceClient>();
-            mockGrpcClient
-                .Setup(m => m.ResolveFloatAsync(
-                    It.IsAny<ResolveFloatRequest>(), null, null, System.Threading.CancellationToken.None))
+            var mockGrpcClient = Substitute.For<Service.ServiceClient>();
+            mockGrpcClient.ResolveFloatAsync(Arg.Any<ResolveFloatRequest>(), null, null, System.Threading.CancellationToken.None)
                 .Returns(grpcResp);
 
-            var flagdProvider = new FlagdProvider(mockGrpcClient.Object, new FlagdConfig());
+            var flagdProvider = new FlagdProvider(mockGrpcClient, new FlagdConfig());
 
             var val = flagdProvider.ResolveDoubleValue("my-key", 0.0, null);
 
@@ -240,13 +241,11 @@ public void TestResolveStructureValue()
                 () => new Grpc.Core.Metadata(),
                 () => { });
 
-            var mockGrpcClient = new Mock<Service.ServiceClient>();
-            mockGrpcClient
-                .Setup(m => m.ResolveObjectAsync(
-                    It.IsAny<ResolveObjectRequest>(), null, null, System.Threading.CancellationToken.None))
+            var mockGrpcClient = Substitute.For<Service.ServiceClient>();
+            mockGrpcClient.ResolveObjectAsync(Arg.Any<ResolveObjectRequest>(), null, null, System.Threading.CancellationToken.None)
                 .Returns(grpcResp);
 
-            var flagdProvider = new FlagdProvider(mockGrpcClient.Object, new FlagdConfig());
+            var flagdProvider = new FlagdProvider(mockGrpcClient, new FlagdConfig());
 
             var val = flagdProvider.ResolveStructureValue("my-key", null, null);
 
@@ -265,13 +264,11 @@ public void TestResolveFlagNotFound()
                 () => new Grpc.Core.Metadata(),
                 () => { });
 
-            var mockGrpcClient = new Mock<Service.ServiceClient>();
-            mockGrpcClient
-                .Setup(m => m.ResolveBooleanAsync(
-                    It.IsAny<ResolveBooleanRequest>(), null, null, System.Threading.CancellationToken.None))
-                .Returns(grpcResp);
+            var mockGrpcClient = Substitute.For<Service.ServiceClient>();
+            mockGrpcClient.ResolveBooleanAsync(
+                    Arg.Any<ResolveBooleanRequest>(), null, null, System.Threading.CancellationToken.None).Returns(grpcResp);
 
-            var flagdProvider = new FlagdProvider(mockGrpcClient.Object, new FlagdConfig());
+            var flagdProvider = new FlagdProvider(mockGrpcClient, new FlagdConfig());
 
             // make sure the correct exception is thrown
             Assert.ThrowsAsync<FeatureProviderException>(async () =>
@@ -301,13 +298,12 @@ public void TestResolveGrpcHostUnavailable()
                 () => new Grpc.Core.Metadata(),
                 () => { });
 
-            var mockGrpcClient = new Mock<Service.ServiceClient>();
-            mockGrpcClient
-                .Setup(m => m.ResolveBooleanAsync(
-                    It.IsAny<ResolveBooleanRequest>(), null, null, System.Threading.CancellationToken.None))
+            var mockGrpcClient = Substitute.For<Service.ServiceClient>();
+            mockGrpcClient.ResolveBooleanAsync(
+                    Arg.Any<ResolveBooleanRequest>(), null, null, System.Threading.CancellationToken.None)
                 .Returns(grpcResp);
 
-            var flagdProvider = new FlagdProvider(mockGrpcClient.Object, new FlagdConfig());
+            var flagdProvider = new FlagdProvider(mockGrpcClient, new FlagdConfig());
 
             // make sure the correct exception is thrown
             Assert.ThrowsAsync<FeatureProviderException>(async () =>
@@ -337,13 +333,12 @@ public void TestResolveTypeMismatch()
                 () => new Grpc.Core.Metadata(),
                 () => { });
 
-            var mockGrpcClient = new Mock<Service.ServiceClient>();
-            mockGrpcClient
-                .Setup(m => m.ResolveBooleanAsync(
-                    It.IsAny<ResolveBooleanRequest>(), null, null, System.Threading.CancellationToken.None))
+            var mockGrpcClient = Substitute.For<Service.ServiceClient>();
+            mockGrpcClient.ResolveBooleanAsync(
+                    Arg.Any<ResolveBooleanRequest>(), null, null, System.Threading.CancellationToken.None)
                 .Returns(grpcResp);
 
-            var flagdProvider = new FlagdProvider(mockGrpcClient.Object, new FlagdConfig());
+            var flagdProvider = new FlagdProvider(mockGrpcClient, new FlagdConfig());
 
             // make sure the correct exception is thrown
             Assert.ThrowsAsync<FeatureProviderException>(async () =>
@@ -373,13 +368,12 @@ public void TestResolveUnknownError()
                 () => new Grpc.Core.Metadata(),
                 () => { });
 
-            var mockGrpcClient = new Mock<Service.ServiceClient>();
-            mockGrpcClient
-                .Setup(m => m.ResolveBooleanAsync(
-                    It.IsAny<ResolveBooleanRequest>(), null, null, System.Threading.CancellationToken.None))
+            var mockGrpcClient = Substitute.For<Service.ServiceClient>();
+            mockGrpcClient.ResolveBooleanAsync(
+                    Arg.Any<ResolveBooleanRequest>(), null, null, System.Threading.CancellationToken.None)
                 .Returns(grpcResp);
 
-            var flagdProvider = new FlagdProvider(mockGrpcClient.Object, new FlagdConfig());
+            var flagdProvider = new FlagdProvider(mockGrpcClient, new FlagdConfig());
 
             // make sure the correct exception is thrown
             Assert.ThrowsAsync<FeatureProviderException>(async () =>
@@ -411,13 +405,12 @@ public void TestCache()
                 () => new Grpc.Core.Metadata(),
                 () => { });
 
-            var mockGrpcClient = new Mock<Service.ServiceClient>();
-            mockGrpcClient
-                .Setup(m => m.ResolveBooleanAsync(
-                    It.IsAny<ResolveBooleanRequest>(), null, null, System.Threading.CancellationToken.None))
+            var mockGrpcClient = Substitute.For<Service.ServiceClient>();
+            mockGrpcClient.ResolveBooleanAsync(
+                    Arg.Any<ResolveBooleanRequest>(), null, null, System.Threading.CancellationToken.None)
                 .Returns(grpcResp);
 
-            var asyncStreamReader = new Mock<IAsyncStreamReader<EventStreamResponse>>();
+            var asyncStreamReader = Substitute.For<IAsyncStreamReader<EventStreamResponse>>();
 
             var l = new List<EventStreamResponse>
             {
@@ -431,8 +424,8 @@ public void TestCache()
             // create an autoResetEvent which we will wait for in our test verification
             var _autoResetEvent = new AutoResetEvent(false);
 
-            asyncStreamReader.Setup(a => a.MoveNext(It.IsAny<System.Threading.CancellationToken>())).ReturnsAsync(() => enumerator.MoveNext());
-            asyncStreamReader.Setup(a => a.Current).Returns(() =>
+            asyncStreamReader.MoveNext(Arg.Any<System.Threading.CancellationToken>()).Returns(enumerator.MoveNext());
+            asyncStreamReader.Current.Returns(_ =>
             {
                 // set the autoResetEvent since this path should be the last one that's reached in the background task
                 _autoResetEvent.Set();
@@ -440,7 +433,7 @@ public void TestCache()
             });
 
             var grpcEventStreamResp = new AsyncServerStreamingCall<EventStreamResponse>(
-                asyncStreamReader.Object,
+                asyncStreamReader,
                 null,
                 null,
                 null,
@@ -448,37 +441,37 @@ public void TestCache()
                 null
             );
 
-            mockGrpcClient
-                .Setup(m => m.EventStream(
-                    It.IsAny<Empty>(), null, null, System.Threading.CancellationToken.None))
+            mockGrpcClient.EventStream(
+                    Arg.Any<Empty>(), null, null, System.Threading.CancellationToken.None)
                 .Returns(grpcEventStreamResp);
 
-            var mockCache = new Mock<ICache<string, object>>();
-            mockCache.Setup(c => c.TryGet(It.Is<string>(s => s == "my-key"))).Returns(() => null);
-            mockCache.Setup(c => c.Add(It.Is<string>(s => s == "my-key"), It.IsAny<object>()));
+            var mockCache = Substitute.For<ICache<string, object>>();
+            mockCache.TryGet(Arg.Is<string>(s => s == "my-key")).Returns(null);
+            mockCache.Add(Arg.Is<string>(s => s == "my-key"), Arg.Any<object>());
 
 
             var config = new FlagdConfig();
             config.CacheEnabled = true;
             config.MaxEventStreamRetries = 1;
-            var flagdProvider = new FlagdProvider(mockGrpcClient.Object, config, mockCache.Object);
+            var flagdProvider = new FlagdProvider(mockGrpcClient, config, mockCache);
 
             // resolve with default set to false to make sure we return what the grpc server gives us
             var val = flagdProvider.ResolveBooleanValue("my-key", false, null);
             Assert.True(val.Result.Value);
 
             Assert.True(_autoResetEvent.WaitOne(10000));
-            mockCache.VerifyAll();
-            mockGrpcClient.VerifyAll();
+            mockCache.Received(1).TryGet(Arg.Is<string>(s => s == "my-key"));
+            mockCache.Received(1).Add(Arg.Is<string>(s => s == "my-key"), Arg.Any<object>());
+            mockGrpcClient.Received(1).EventStream(Arg.Any<Empty>(), null, null, System.Threading.CancellationToken.None);
         }
 
         [Fact]
         public void TestCacheHit()
         {
 
-            var mockGrpcClient = new Mock<Service.ServiceClient>();
+            var mockGrpcClient = Substitute.For<Service.ServiceClient>();
 
-            var asyncStreamReader = new Mock<IAsyncStreamReader<EventStreamResponse>>();
+            var asyncStreamReader = Substitute.For<IAsyncStreamReader<EventStreamResponse>>();
 
             var l = new List<EventStreamResponse>
             {
@@ -492,8 +485,8 @@ public void TestCacheHit()
             // create an autoResetEvent which we will wait for in our test verification
             AutoResetEvent _autoResetEvent = new AutoResetEvent(false);
 
-            asyncStreamReader.Setup(a => a.MoveNext(It.IsAny<System.Threading.CancellationToken>())).ReturnsAsync(() => enumerator.MoveNext());
-            asyncStreamReader.Setup(a => a.Current).Returns(() =>
+            asyncStreamReader.MoveNext(Arg.Any<System.Threading.CancellationToken>()).Returns(enumerator.MoveNext());
+            asyncStreamReader.Current.Returns(_ =>
             {
                 // set the autoResetEvent since this path should be the last one that's reached in the background task
                 _autoResetEvent.Set();
@@ -501,7 +494,7 @@ public void TestCacheHit()
             });
 
             var grpcEventStreamResp = new AsyncServerStreamingCall<EventStreamResponse>(
-                asyncStreamReader.Object,
+                asyncStreamReader,
                 null,
                 null,
                 null,
@@ -509,20 +502,19 @@ public void TestCacheHit()
                 null
             );
 
-            mockGrpcClient
-                .Setup(m => m.EventStream(
-                    It.IsAny<Empty>(), null, null, System.Threading.CancellationToken.None))
+            mockGrpcClient.EventStream(
+                    Arg.Any<Empty>(), null, null, System.Threading.CancellationToken.None)
                 .Returns(grpcEventStreamResp);
 
-            var mockCache = new Mock<ICache<string, object>>();
-            mockCache.Setup(c => c.TryGet(It.Is<string>(s => s == "my-key"))).Returns(
-                () => new ResolutionDetails<bool>("my-key", true)
-            );
+            var mockCache = Substitute.For<ICache<string, object>>();
+            mockCache.TryGet("my-key").Returns(new ResolutionDetails<bool>("my-key", true));
 
-            var config = new FlagdConfig();
-            config.CacheEnabled = true;
-            config.MaxEventStreamRetries = 1;
-            var flagdProvider = new FlagdProvider(mockGrpcClient.Object, config, mockCache.Object);
+            var config = new FlagdConfig
+            {
+                CacheEnabled = true,
+                MaxEventStreamRetries = 1
+            };
+            var flagdProvider = new FlagdProvider(mockGrpcClient, config, mockCache);
 
             // resolve with default set to false to make sure we return what the grpc server gives us
             var val = flagdProvider.ResolveBooleanValue("my-key", false, null);
@@ -530,8 +522,8 @@ public void TestCacheHit()
 
             // wait for the autoReset event to be fired before verifying the invocation of the mocked functions
             Assert.True(_autoResetEvent.WaitOne(10000));
-            mockCache.VerifyAll();
-            mockGrpcClient.VerifyAll();
+            mockCache.Received(1).TryGet("my-key");
+            mockGrpcClient.Received(1).EventStream(Arg.Any<Empty>(), null, null, System.Threading.CancellationToken.None);
         }
 
         [Fact]
@@ -548,13 +540,12 @@ public void TestCacheInvalidation()
                 () => new Grpc.Core.Metadata(),
                 () => { });
 
-            var mockGrpcClient = new Mock<Service.ServiceClient>();
-            mockGrpcClient
-                .Setup(m => m.ResolveBooleanAsync(
-                    It.IsAny<ResolveBooleanRequest>(), null, null, System.Threading.CancellationToken.None))
+            var mockGrpcClient = Substitute.For<Service.ServiceClient>();
+            mockGrpcClient.ResolveBooleanAsync(
+                    Arg.Any<ResolveBooleanRequest>(), null, null, System.Threading.CancellationToken.None)
                 .Returns(grpcResp);
 
-            var asyncStreamReader = new Mock<IAsyncStreamReader<EventStreamResponse>>();
+            var asyncStreamReader = Substitute.For<IAsyncStreamReader<EventStreamResponse>>();
 
             var configurationChangeData = new Struct();
             var changedFlag = new Struct();
@@ -564,7 +555,7 @@ public void TestCacheInvalidation()
 
             var firstCall = true;
 
-            asyncStreamReader.Setup(a => a.MoveNext(It.IsAny<System.Threading.CancellationToken>())).ReturnsAsync(() => true);
+            asyncStreamReader.MoveNext(Arg.Any<System.Threading.CancellationToken>()).Returns(true);
             // as long as we did not send our first request to the provider, we will not send a configuration_change event
             // after the value of the flag has been retrieved the first time, we will send a configuration_change to test if the
             // item is deleted from the cache
@@ -572,8 +563,8 @@ public void TestCacheInvalidation()
             // create an autoResetEvent which we will wait for in our test verification
             AutoResetEvent _autoResetEvent = new AutoResetEvent(false);
 
-            asyncStreamReader.Setup(a => a.Current).Returns(
-                () =>
+            asyncStreamReader.Current.Returns(
+                _ =>
                 {
                     if (firstCall)
                     {
@@ -591,7 +582,7 @@ public void TestCacheInvalidation()
             );
 
             var grpcEventStreamResp = new AsyncServerStreamingCall<EventStreamResponse>(
-                asyncStreamReader.Object,
+                asyncStreamReader,
                 null,
                 null,
                 null,
@@ -599,18 +590,14 @@ public void TestCacheInvalidation()
                 null
             );
 
-            mockGrpcClient
-                .Setup(m => m.EventStream(
-                    It.IsAny<Empty>(), null, null, System.Threading.CancellationToken.None))
-                .Returns(() =>
-                {
-                    return grpcEventStreamResp;
-                });
+            mockGrpcClient.EventStream(
+                    Arg.Any<Empty>(), null, null, System.Threading.CancellationToken.None)
+                .Returns(grpcEventStreamResp);
 
-            var mockCache = new Mock<ICache<string, object>>();
-            mockCache.Setup(c => c.TryGet(It.Is<string>(s => s == "my-key"))).Returns(() => null);
-            mockCache.Setup(c => c.Add(It.Is<string>(s => s == "my-key"), It.IsAny<object>()));
-            mockCache.Setup(c => c.Delete(It.Is<string>(s => s == "my-key"))).Callback(() =>
+            var mockCache = Substitute.For<ICache<string, object>>();
+            mockCache.TryGet(Arg.Is<string>(s => s == "my-key")).Returns(null);
+            mockCache.Add(Arg.Is<string>(s => s == "my-key"), Arg.Any<object>());
+            mockCache.When(x => x.Delete("my-key")).Do(_ =>
             {
                 // set the autoResetEvent since this path should be the last one that's reached in the background task
                 _autoResetEvent.Set();
@@ -620,7 +607,7 @@ public void TestCacheInvalidation()
             var config = new FlagdConfig();
             config.CacheEnabled = true;
             config.MaxEventStreamRetries = 1;
-            var flagdProvider = new FlagdProvider(mockGrpcClient.Object, config, mockCache.Object);
+            var flagdProvider = new FlagdProvider(mockGrpcClient, config, mockCache);
 
             // resolve with default set to false to make sure we return what the grpc server gives us
             var val = flagdProvider.ResolveBooleanValue("my-key", false, null);
@@ -634,8 +621,10 @@ public void TestCacheInvalidation()
 
             Assert.True(_autoResetEvent.WaitOne(10000));
 
-            mockCache.VerifyAll();
-            mockGrpcClient.VerifyAll();
+            mockCache.Received(2).TryGet("my-key");
+            mockCache.Received(2).Add("my-key", Arg.Any<object>());
+            mockCache.Received().Delete("my-key");
+            mockGrpcClient.Received(1).EventStream(Arg.Any<Empty>(), null, null, System.Threading.CancellationToken.None);
         }
     }
 }
diff --git a/test/OpenFeature.Contrib.Providers.GOFeatureFlag.Test/HttpClientMock.cs b/test/OpenFeature.Contrib.Providers.GOFeatureFlag.Test/HttpClientMock.cs
deleted file mode 100644
index 6af6bbf2..00000000
--- a/test/OpenFeature.Contrib.Providers.GOFeatureFlag.Test/HttpClientMock.cs
+++ /dev/null
@@ -1,34 +0,0 @@
-using System.Net;
-using System.Net.Http;
-using System.Net.Http.Headers;
-using System.Text.Json;
-using System.Threading;
-using System.Threading.Tasks;
-using Moq;
-using Moq.Protected;
-
-namespace OpenFeature.Contrib.Providers.GOFeatureFlag.Test;
-
-public class HttpClientMock
-{
-    public static Mock<HttpMessageHandler> GetResults<T>(T response)
-    {
-        var mockResponse = new HttpResponseMessage
-        {
-            Content = new StringContent(JsonSerializer.Serialize(response)),
-            StatusCode = HttpStatusCode.OK
-        };
-
-        mockResponse.Content.Headers.ContentType =
-            new MediaTypeHeaderValue("application/json");
-        var mockHandler = new Mock<HttpMessageHandler>();
-        mockHandler
-            .Protected()
-            .Setup<Task<HttpResponseMessage>>(
-                "SendAsync",
-                ItExpr.IsAny<HttpRequestMessage>(),
-                ItExpr.IsAny<CancellationToken>())
-            .ReturnsAsync(mockResponse);
-        return mockHandler;
-    }
-}
\ No newline at end of file