diff --git a/PKHeX.Core/Legality/Enums/SlotType.cs b/PKHeX.Core/Legality/Enums/SlotType.cs
index bb74206b3..4c28b05ab 100644
--- a/PKHeX.Core/Legality/Enums/SlotType.cs
+++ b/PKHeX.Core/Legality/Enums/SlotType.cs
@@ -85,10 +85,12 @@ public enum SlotType : byte
         /// </summary>
         SOS = 15,
 
+        // Legends: Arceus
         Overworld = 16,
         Distortion = 17,
         Landmark = 18,
-        OverworldMMO = 19,
+        OverworldMass = 19,
+        OverworldMMO = 20,
 
         // Modifiers
 
diff --git a/PKHeX.Core/Resources/legality/wild/Gen8/encounter_la.pkl b/PKHeX.Core/Resources/legality/wild/Gen8/encounter_la.pkl
index 34b3a3aad..a3a4244ac 100644
Binary files a/PKHeX.Core/Resources/legality/wild/Gen8/encounter_la.pkl and b/PKHeX.Core/Resources/legality/wild/Gen8/encounter_la.pkl differ