diff --git a/FastRng/Double/Distributions/Normal.cs b/FastRng/Double/Distributions/Normal.cs
index 58fb8a9..ea7b6b8 100644
--- a/FastRng/Double/Distributions/Normal.cs
+++ b/FastRng/Double/Distributions/Normal.cs
@@ -8,7 +8,7 @@ namespace FastRng.Double.Distributions
     public sealed class Normal : IDistribution
     {
         private const double SQRT_2PI = 2.506628275;
-        private const double STDDEV = 0.4;
+        private const double STDDEV = 0.2;
         private const double MEAN = 0.5;
         
         private ShapeFitter fitter;
@@ -24,11 +24,11 @@ namespace FastRng.Double.Distributions
             set
             {
                 this.random = value;
-                this.fitter = new ShapeFitter(Normal.ShapeFunction, this.random, 50, 0.99);
+                this.fitter = new ShapeFitter(Normal.ShapeFunction, this.random, 50, 1.93);
             }
         }
         
-        private static double ShapeFunction(double x) => 1.0 / (STDDEV * SQRT_2PI) * Math.Exp(-Math.Pow((x - MEAN) / STDDEV, 2.0));
+        private static double ShapeFunction(double x) => 1.0 / (STDDEV * SQRT_2PI) * Math.Exp(-0.5 * Math.Pow((x - MEAN) / STDDEV, 2.0));
 
         public async ValueTask<double> GetDistributedValue(CancellationToken token = default)
         {