diff --git a/PKHeX.Core/PKM/PK7.cs b/PKHeX.Core/PKM/PK7.cs
index 82980216f..a325dae88 100644
--- a/PKHeX.Core/PKM/PK7.cs
+++ b/PKHeX.Core/PKM/PK7.cs
@@ -78,7 +78,7 @@ public override uint EXP
             set => BitConverter.GetBytes(value).CopyTo(Data, 0x10);
         }
         public override int Ability { get => Data[0x14]; set => Data[0x14] = (byte)value; }
-        public override int AbilityNumber { get => Data[0x15]; set => Data[0x15] = (byte)value; }
+        public override int AbilityNumber { get => Data[0x15] & 7; set => Data[0x15] = (byte)(Data[0x15] & ~7 | value & 7); }
         public override int MarkValue { get => BitConverter.ToUInt16(Data, 0x16); protected set => BitConverter.GetBytes((ushort)value).CopyTo(Data, 0x16); }
         public override uint PID
         {