1 files changed, 1 insertions, 1 deletions
diff --git a/Day6.cs b/Day6.cs
index de59f99..50dd605 100644
--- a/Day6.cs
+++ b/Day6.cs
@@ -3,7 +3,7 @@ using System.Linq;
 
 namespace aoc2019
 {
-    internal class Day6 : Day
+    internal sealed class Day6 : Day
     {
         public override int DayNumber => 6;