diff --git a/src/battle.ts b/src/battle.ts
index 07e7a7187cb..6086c2ceb4e 100644
--- a/src/battle.ts
+++ b/src/battle.ts
@@ -19,7 +19,6 @@ import { MysteryEncounterMode } from "#enums/mystery-encounter-mode";
 import { CustomModifierSettings } from "#app/modifier/modifier-type";
 import { ModifierTier } from "#app/modifier/modifier-tier";
 import { MysteryEncounterType } from "#enums/mystery-encounter-type";
-import { isNullOrUndefined } from "./utils";
 
 export enum ClassicFixedBossWaves {
   // TODO: other fixed wave battles should be added here
@@ -415,7 +414,7 @@ export default class Battle {
    * Returns if the battle is of type {@linkcode BattleType.MYSTERY_ENCOUNTER}
    */
   isBattleMysteryEncounter(): boolean {
-    return !isNullOrUndefined(this.battleType) && this.battleType === BattleType.MYSTERY_ENCOUNTER;
+    return this.battleType === BattleType.MYSTERY_ENCOUNTER;
   }
 }
 
diff --git a/src/phases/encounter-phase.ts b/src/phases/encounter-phase.ts
index 321e83370c5..6cdf6c55af8 100644
--- a/src/phases/encounter-phase.ts
+++ b/src/phases/encounter-phase.ts
@@ -253,8 +253,8 @@ export class EncounterPhase extends BattlePhase {
         this.scene.updateModifiers(true);
       }*/
 
-    const { battleType, waveIndex, isBattleMysteryEncounter } = this.scene.currentBattle;
-    if (this.scene.isMysteryEncounterValidForWave(battleType,  waveIndex) && !isBattleMysteryEncounter()) {
+    const { battleType, waveIndex } = this.scene.currentBattle;
+    if (this.scene.isMysteryEncounterValidForWave(battleType,  waveIndex) && !this.scene.currentBattle.isBattleMysteryEncounter()) {
       // Increment ME spawn chance if an ME could have spawned but did not
       // Only do this AFTER session has been saved to avoid duplicating increments
       this.scene.mysteryEncounterSaveData.encounterSpawnChance += WEIGHT_INCREMENT_ON_SPAWN_MISS;