1 files changed, 1 insertions, 1 deletions
diff --git a/Day7.cs b/Day7.cs
index 349e638..7f94e5a 100644
--- a/Day7.cs
+++ b/Day7.cs
@@ -4,7 +4,7 @@ using System.Linq;
 
 namespace aoc2019
 {
-    internal class Day7 : Day
+    internal sealed class Day7 : Day
     {
         public override int DayNumber => 7;