diff --git a/src/battle-scene.ts b/src/battle-scene.ts
index ae6cea2dcd1..4faf3863e3c 100644
--- a/src/battle-scene.ts
+++ b/src/battle-scene.ts
@@ -2419,13 +2419,7 @@ export default class BattleScene extends SceneBase {
           count = Math.max(count, Math.floor(chances / 2));
         }
         getEnemyModifierTypesForWave(difficultyWaveIndex, count, [ enemyPokemon ], this.currentBattle.battleType === BattleType.TRAINER ? ModifierPoolType.TRAINER : ModifierPoolType.WILD, upgradeChance)
-          .map(mt => {
-            const enemyModifier = mt.newModifier(enemyPokemon);
-            if (enemyModifier instanceof TurnHeldItemTransferModifier) {
-              enemyModifier.setTransferrableFalse();
-            }
-            enemyModifier.add(this.enemyModifiers, false, this);
-          });
+          .map(mt => mt.newModifier(enemyPokemon).add(this.enemyModifiers, false, this));
       });
       this.updateModifiers(false).then(() => resolve());
     });
diff --git a/src/phases.ts b/src/phases.ts
index 565914879e4..c50d25acf60 100644
--- a/src/phases.ts
+++ b/src/phases.ts
@@ -878,6 +878,10 @@ export class EncounterPhase extends BattlePhase {
         } else if (!(battle.waveIndex % 1000)) {
           enemyPokemon.formIndex = 1;
           enemyPokemon.updateScale();
+          const bossMBH = this.scene.findModifier(m => m instanceof TurnHeldItemTransferModifier && m.pokemonId === enemyPokemon.id, false) as TurnHeldItemTransferModifier;
+          this.scene.removeModifier(bossMBH!);
+          bossMBH?.setTransferrableFalse();
+          this.scene.addEnemyModifier(bossMBH!);
         }
       }