1 files changed, 1 insertions, 1 deletions
diff --git a/Day11.cs b/Day11.cs
index 005d32d..4fc323b 100644
--- a/Day11.cs
+++ b/Day11.cs
@@ -5,7 +5,7 @@ using System.Linq;
 
 namespace aoc2019
 {
-    internal class Day11 : Day
+    internal sealed class Day11 : Day
     {
         public override int DayNumber => 11;