diff --git a/FastRngTests/Double/Distributions/Beta.cs b/FastRngTests/Double/Distributions/Beta.cs
index 5da90b9..e7f4636 100644
--- a/FastRngTests/Double/Distributions/Beta.cs
+++ b/FastRngTests/Double/Distributions/Beta.cs
@@ -32,8 +32,8 @@ namespace FastRngTests.Double.Distributions
             TestContext.WriteLine($"mean={MEAN} vs. {stats.Mean}");
             TestContext.WriteLine($"variance={VARIANCE} vs {stats.Variance}");
             
-            Assert.That(stats.Mean, Is.EqualTo(MEAN).Within(0.4), "Mean is out of range");
-            Assert.That(stats.Variance, Is.EqualTo(VARIANCE).Within(0.4), "Variance is out of range");
+            Assert.That(stats.Mean, Is.EqualTo(MEAN).Within(0.1), "Mean is out of range");
+            Assert.That(stats.Variance, Is.EqualTo(VARIANCE).Within(0.01), "Variance is out of range");
         }
         
         [Test]
diff --git a/FastRngTests/Double/Distributions/Exponential.cs b/FastRngTests/Double/Distributions/Exponential.cs
index 6f41ee8..872edc5 100644
--- a/FastRngTests/Double/Distributions/Exponential.cs
+++ b/FastRngTests/Double/Distributions/Exponential.cs
@@ -29,8 +29,8 @@ namespace FastRngTests.Double.Distributions
             TestContext.WriteLine($"mean={MEAN} vs. {stats.Mean}");
             TestContext.WriteLine($"variance={VARIANCE} vs {stats.Variance}");
             
-            Assert.That(stats.Mean, Is.EqualTo(MEAN).Within(0.4), "Mean is out of range");
-            Assert.That(stats.Variance, Is.EqualTo(VARIANCE).Within(0.4), "Variance is out of range");
+            Assert.That(stats.Mean, Is.EqualTo(MEAN).Within(0.1), "Mean is out of range");
+            Assert.That(stats.Variance, Is.EqualTo(VARIANCE).Within(0.1), "Variance is out of range");
         }
         
         [Test]
diff --git a/FastRngTests/Double/Distributions/Gamma.cs b/FastRngTests/Double/Distributions/Gamma.cs
index d02eff7..40e2563 100644
--- a/FastRngTests/Double/Distributions/Gamma.cs
+++ b/FastRngTests/Double/Distributions/Gamma.cs
@@ -58,8 +58,8 @@ namespace FastRngTests.Double.Distributions
             TestContext.WriteLine($"mean={MEAN} vs. {stats.Mean}");
             TestContext.WriteLine($"variance={VARIANCE} vs {stats.Variance}");
             
-            Assert.That(stats.Mean, Is.EqualTo(MEAN).Within(0.4), "Mean is out of range");
-            Assert.That(stats.Variance, Is.EqualTo(VARIANCE).Within(0.4), "Variance is out of range");
+            Assert.That(stats.Mean, Is.EqualTo(MEAN).Within(0.1), "Mean is out of range");
+            Assert.That(stats.Variance, Is.EqualTo(VARIANCE).Within(0.1), "Variance is out of range");
         }
         
         [Test]
diff --git a/FastRngTests/Double/Distributions/InverseGamma.cs b/FastRngTests/Double/Distributions/InverseGamma.cs
index 4cdfe59..45956bf 100644
--- a/FastRngTests/Double/Distributions/InverseGamma.cs
+++ b/FastRngTests/Double/Distributions/InverseGamma.cs
@@ -31,8 +31,8 @@ namespace FastRngTests.Double.Distributions
             TestContext.WriteLine($"mean={MEAN} vs. {stats.Mean}");
             TestContext.WriteLine($"variance={VARIANCE} vs {stats.Variance}");
             
-            Assert.That(stats.Mean, Is.EqualTo(MEAN).Within(0.4), "Mean is out of range");
-            Assert.That(stats.Variance, Is.EqualTo(VARIANCE).Within(0.4), "Variance is out of range");
+            Assert.That(stats.Mean, Is.EqualTo(MEAN).Within(0.1), "Mean is out of range");
+            Assert.That(stats.Variance, Is.EqualTo(VARIANCE).Within(0.1), "Variance is out of range");
         }
         
         [Test]
diff --git a/FastRngTests/Double/Distributions/Laplace.cs b/FastRngTests/Double/Distributions/Laplace.cs
index 7c5e1bc..462ea80 100644
--- a/FastRngTests/Double/Distributions/Laplace.cs
+++ b/FastRngTests/Double/Distributions/Laplace.cs
@@ -30,8 +30,8 @@ namespace FastRngTests.Double.Distributions
             TestContext.WriteLine($"mean={MEAN} vs. {stats.Mean}");
             TestContext.WriteLine($"variance={VARIANCE} vs {stats.Variance}");
             
-            Assert.That(stats.Mean, Is.EqualTo(MEAN).Within(0.4), "Mean is out of range");
-            Assert.That(stats.Variance, Is.EqualTo(VARIANCE).Within(0.4), "Variance is out of range");
+            Assert.That(stats.Mean, Is.EqualTo(MEAN).Within(0.1), "Mean is out of range");
+            Assert.That(stats.Variance, Is.EqualTo(VARIANCE).Within(0.5), "Variance is out of range");
         }
         
         [Test]
diff --git a/FastRngTests/Double/Distributions/Normal.cs b/FastRngTests/Double/Distributions/Normal.cs
index a2bc05f..5dd7808 100644
--- a/FastRngTests/Double/Distributions/Normal.cs
+++ b/FastRngTests/Double/Distributions/Normal.cs
@@ -10,6 +10,9 @@ namespace FastRngTests.Double.Distributions
     [ExcludeFromCodeCoverage]
     public class Normal
     {
+        [Test]
+        [Category(TestCategories.COVER)]
+        [Category(TestCategories.NORMAL)]
         public async Task TestNormalDistribution01()
         {
             const double DESIRED_MEAN = 2.0;