diff --git a/PKHeX.Core/Legality/Breeding.cs b/PKHeX.Core/Legality/Breeding.cs
index 2b9629241..b17dad3fe 100644
--- a/PKHeX.Core/Legality/Breeding.cs
+++ b/PKHeX.Core/Legality/Breeding.cs
@@ -25,6 +25,8 @@ public static class Breeding
             X, Y, OR, AS,
             SN, MN, US, UM,
             SW, SH,
+
+            GS,
         };
 
         /// <summary>