diff --git a/Tests/Testably.Abstractions.Tests/TimeSystem/StopwatchTests.cs b/Tests/Testably.Abstractions.Tests/TimeSystem/StopwatchTests.cs
index 7addd072..6caedc02 100644
--- a/Tests/Testably.Abstractions.Tests/TimeSystem/StopwatchTests.cs
+++ b/Tests/Testably.Abstractions.Tests/TimeSystem/StopwatchTests.cs
@@ -136,7 +136,8 @@ public async Task Stop_ShouldSetIsRunningToFalse()
 		stopwatch.Stop();
 		TimeSpan elapsed = stopwatch.Elapsed;
 
-		await That(elapsed.TotalMilliseconds).IsGreaterThanOrEqualTo(100);
+		// Allow one millisecond tolerance due to potential rounding issues.
+		await That(elapsed.TotalMilliseconds).IsGreaterThanOrEqualTo(99);
 		await That(stopwatch.IsRunning).IsFalse();
 	}