diff --git a/pflib-net.Tests/dice/DiceTest.cs b/pflib-net.Tests/dice/DiceTest.cs
index 17e55b9..f3f6bea 100644
--- a/pflib-net.Tests/dice/DiceTest.cs
+++ b/pflib-net.Tests/dice/DiceTest.cs
@@ -49,10 +49,9 @@ public class DiceTest
     }
 
     [Test]
-    [TestCase(1, 1)]
-    public void CannotSetKeepHighestAndKeepLowest(int high, int low)
+    public void CannotSetKeepHighestAndKeepLowest()
     {
         var e = Assert.Throws<InvalidOperationException>(
-            () => new Dice(1, 40, high, low));
+            () => new Dice(1, 40, 1, 1));
     }
 }
\ No newline at end of file
diff --git a/pflib-net/dice/Dice.cs b/pflib-net/dice/Dice.cs
index 383054d..87310aa 100644
--- a/pflib-net/dice/Dice.cs
+++ b/pflib-net/dice/Dice.cs
@@ -7,6 +7,7 @@ public struct Dice
     private int KeepHighest { get; set; }
     private int KeepLowest { get; set; }
     private int Add { get; set; }
+    private static readonly Random Random = new();
 
     public Dice(int size, int count = 1, int keepHighest = 0, int keepLowest = 0, int add = 0)
     {
@@ -24,11 +25,10 @@ public struct Dice
 
     public int GetValue()
     {
-        var random = new Random();
         var rolls = new List<int>();
         for (var i = 0; i < Count; i++)
         {
-            rolls.Add(random.Next(Size) + 1);
+            rolls.Add(Random.Next(Size) + 1);
         }
         rolls.Sort();