1 files changed, 1 insertions, 1 deletions
diff --git a/Day1.cs b/Day1.cs
index 2d3ef67..53b808c 100644
--- a/Day1.cs
+++ b/Day1.cs
@@ -3,7 +3,7 @@ using System.Linq;
 
 namespace aoc2019
 {
-    public class Day1 : Day
+    internal sealed class Day1 : Day
     {
         public override int DayNumber => 1;