diff --git a/src/ConfigCat.Client.Tests/ConfigServiceTests.cs b/src/ConfigCat.Client.Tests/ConfigServiceTests.cs
index feb462c3..f9d39139 100644
--- a/src/ConfigCat.Client.Tests/ConfigServiceTests.cs
+++ b/src/ConfigCat.Client.Tests/ConfigServiceTests.cs
@@ -194,6 +194,8 @@ public async Task LazyLoadConfigService_RefreshConfigAsync_ConfigChanged_ShouldR
 
         await service.RefreshConfigAsync();
 
+        GC.KeepAlive(hooks);
+
         // Assert
 
         Assert.IsTrue(configChangedEvents.TryDequeue(out var configChangedEvent));
@@ -456,6 +458,8 @@ public async Task ManualPollConfigService_GetConfigAsync_ShouldInvokeCacheGet()
 
         var projectConfig = await service.GetConfigAsync();
 
+        GC.KeepAlive(hooks);
+
         // Assert
 
         Assert.AreEqual(cachedPc, projectConfig);
@@ -508,10 +512,13 @@ public async Task ManualPollConfigService_RefreshConfigAsync_ShouldInvokeCacheGe
             new CacheParameters(this.cacheMock.Object, cacheKey: null!),
             this.loggerMock.Object.AsWrapper(),
             hooks: hooks);
+
         // Act
 
         await service.RefreshConfigAsync();
 
+        GC.KeepAlive(hooks);
+
         // Assert
 
         this.cacheMock.Verify(m => m.GetAsync(It.IsAny<string>(), It.IsAny<CancellationToken>()), Times.Exactly(2));
@@ -566,6 +573,8 @@ public async Task ManualPollConfigService_RefreshConfigAsync_ConfigChanged_Shoul
 
         await service.RefreshConfigAsync();
 
+        GC.KeepAlive(hooks);
+
         // Assert
 
         Assert.IsTrue(configChangedEvents.TryDequeue(out var configChangedEvent));
@@ -699,6 +708,8 @@ public async Task AutoPollConfigService_GetConfig_ReturnsCachedConfigWhenCachedC
             actualPc = isAsync ? await service.GetConfigAsync() : service.GetConfig();
         }
 
+        GC.KeepAlive(hooks);
+
         // Assert
 
         Assert.AreEqual(cachedPc, actualPc);
@@ -762,10 +773,14 @@ public async Task AutoPollConfigService_GetConfig_FetchesConfigWhenCachedConfigI
             cts.Cancel();
             clientReadyCalled = task == clientReadyTask && task.Status == TaskStatus.RanToCompletion;
 
+            await Task.Yield();
+
             // Wait for the hook event handlers to execute (as that might not happen if the service got disposed immediately).
             SpinWait.SpinUntil(() => configFetchedEvents.TryPeek(out _), TimeSpan.FromSeconds(1));
         }
 
+        GC.KeepAlive(hooks);
+
         // Assert
 
         Assert.AreEqual(fetchedPc, actualPc);
@@ -835,10 +850,14 @@ public async Task AutoPollConfigService_GetConfig_ReturnsExpiredConfigWhenCantRe
             cts.Cancel();
             clientReadyCalled = task == clientReadyTask && task.Status == TaskStatus.RanToCompletion;
 
+            await Task.Yield();
+
             // Wait for the hook event handlers to execute (as that might not happen if the service got disposed immediately).
             SpinWait.SpinUntil(() => configFetchedEvents.TryPeek(out _), TimeSpan.FromSeconds(1));
         }
 
+        GC.KeepAlive(hooks);
+
         // Assert
 
         Assert.AreEqual(fetchedPc, actualPc);
@@ -900,6 +919,9 @@ public async Task LazyLoadConfigService_GetConfig_ReturnsCachedConfigWhenCachedC
         {
             actualPc = isAsync ? await service.GetConfigAsync() : service.GetConfig();
         }
+
+        GC.KeepAlive(hooks);
+
         // Assert
 
         Assert.AreEqual(cachedPc, actualPc);
@@ -964,6 +986,9 @@ public async Task LazyLoadConfigService_GetConfig_FetchesConfigWhenCachedConfigI
         {
             actualPc = isAsync ? await service.GetConfigAsync() : service.GetConfig();
         }
+
+        GC.KeepAlive(hooks);
+
         // Assert
 
         Assert.AreEqual(fetchedPc, actualPc);
diff --git a/src/ConfigCat.Client.Tests/SynchronizationContextDeadlockTests.cs b/src/ConfigCat.Client.Tests/SynchronizationContextDeadlockTests.cs
index 18f3a45d..2d4961d3 100644
--- a/src/ConfigCat.Client.Tests/SynchronizationContextDeadlockTests.cs
+++ b/src/ConfigCat.Client.Tests/SynchronizationContextDeadlockTests.cs
@@ -60,7 +60,7 @@ public void AutoPollDeadLockCheck()
     [TestMethod]
     public void ManualPollDeadLockCheck()
     {
-        var client = ConfigCatClient.Get(SDKKEY, options =>
+        using var client = ConfigCatClient.Get(SDKKEY, options =>
         {
             options.Logger = new ConsoleLogger(LogLevel.Off);
             options.HttpClientHandler = SharedHandler;
@@ -72,7 +72,7 @@ public void ManualPollDeadLockCheck()
     [TestMethod]
     public void LazyLoadDeadLockCheck()
     {
-        var client = ConfigCatClient.Get(SDKKEY, options =>
+        using var client = ConfigCatClient.Get(SDKKEY, options =>
         {
             options.Logger = new ConsoleLogger(LogLevel.Off);
             options.HttpClientHandler = SharedHandler;