diff --git a/tests/Healthie.Tests.Unit/DiagnosticsTests.cs b/tests/Healthie.Tests.Unit/DiagnosticsTests.cs
index 7bf46b1..f741959 100644
--- a/tests/Healthie.Tests.Unit/DiagnosticsTests.cs
+++ b/tests/Healthie.Tests.Unit/DiagnosticsTests.cs
@@ -178,7 +178,7 @@ public async Task ATransition_IsCountedOnceAndNotOnEveryTick()
 
         Assert.Equal(1, afterTheChange);
         Assert.Equal(3, For("healthie.check.results", name).Count);
-        Assert.Equal(1, For("healthie.check.transitions", name).Count);
+        Assert.Single(For("healthie.check.transitions", name));
     }
 
     /// <summary>
diff --git a/tests/Healthie.Tests.Unit/HardeningTests.cs b/tests/Healthie.Tests.Unit/HardeningTests.cs
index 8521898..120f747 100644
--- a/tests/Healthie.Tests.Unit/HardeningTests.cs
+++ b/tests/Healthie.Tests.Unit/HardeningTests.cs
@@ -19,7 +19,7 @@ public void ADashboardTitle_CannotCloseTheTitleElement()
         var page = Healthie.Dashboard.StartupExtensions.BuildPage("</title><script>alert(1)</script>");
 
         // One closing title tag: the one the page itself writes.
-        Assert.Equal(1, Regex.Matches(page, "</title>", RegexOptions.IgnoreCase).Count);
+        Assert.Single(Regex.Matches(page, "</title>", RegexOptions.IgnoreCase));
         Assert.DoesNotContain("<script>alert", page, StringComparison.OrdinalIgnoreCase);
     }
 
diff --git a/tests/Healthie.Tests.Unit/RedisStateProviderTests.cs b/tests/Healthie.Tests.Unit/RedisStateProviderTests.cs
index 2daa91f..d05ce18 100644
--- a/tests/Healthie.Tests.Unit/RedisStateProviderTests.cs
+++ b/tests/Healthie.Tests.Unit/RedisStateProviderTests.cs
@@ -31,7 +31,7 @@ public async ValueTask InitializeAsync()
     {
         try
         {
-            _redis = new RedisBuilder().WithImage("redis:7-alpine").Build();
+            _redis = new RedisBuilder("redis:7-alpine").Build();
             await _redis.StartAsync(Ct);
             _connection = await ConnectionMultiplexer.ConnectAsync(_redis.GetConnectionString());
         }
diff --git a/tests/Healthie.Tests.Unit/UptimeTests.cs b/tests/Healthie.Tests.Unit/UptimeTests.cs
index d8c8737..f51a8d0 100644
--- a/tests/Healthie.Tests.Unit/UptimeTests.cs
+++ b/tests/Healthie.Tests.Unit/UptimeTests.cs
@@ -331,7 +331,7 @@ public async Task RepeatedNonTransitions_NeverReachTheQueue()
                 checker.RaiseStateChanged(PulseCheckerHealth.Unhealthy);
             }
 
-            await Task.Delay(200);
+            await Task.Delay(200, TestContext.Current.CancellationToken);
 
             Assert.Equal(0, recorder.DroppedCount);
         }