diff --git a/src/data/battler-tags.ts b/src/data/battler-tags.ts
index b12d15968f6..02a7affbe9c 100644
--- a/src/data/battler-tags.ts
+++ b/src/data/battler-tags.ts
@@ -887,7 +887,7 @@ export class HighestStatBoostTag extends AbilityBattlerTag {
     stats.map(s => pokemon.getBattleStat(s)).reduce((highestValue: integer, value: integer, i: integer) => {
       if (value > highestValue) {
         highestStat = stats[i];
-        return highestValue += value;
+        return highestValue = value;
       }
       return highestValue;
     }, 0);
diff --git a/src/field/pokemon.ts b/src/field/pokemon.ts
index 97b228a24ca..2c3c746bfee 100644
--- a/src/field/pokemon.ts
+++ b/src/field/pokemon.ts
@@ -19,7 +19,7 @@ import { pokemonEvolutions, pokemonPrevolutions, SpeciesFormEvolution, SpeciesEv
 import { reverseCompatibleTms, tmSpecies } from '../data/tms';
 import { DamagePhase, FaintPhase, LearnMovePhase, ObtainStatusEffectPhase, StatChangePhase, SwitchSummonPhase } from '../phases';
 import { BattleStat } from '../data/battle-stat';
-import { BattlerTag, BattlerTagLapseType, EncoreTag, HelpingHandTag, TypeBoostTag, getBattlerTag } from '../data/battler-tags';
+import { BattlerTag, BattlerTagLapseType, EncoreTag, HelpingHandTag, HighestStatBoostTag, TypeBoostTag, getBattlerTag } from '../data/battler-tags';
 import { BattlerTagType } from "../data/enums/battler-tag-type";
 import { Species } from '../data/enums/species';
 import { WeatherType } from '../data/weather';
@@ -579,7 +579,11 @@ export default abstract class Pokemon extends Phaser.GameObjects.Container {
           ret >>= 1;
         break;
     }
-    
+
+    const highestStatBoost = this.findTag(t => t instanceof HighestStatBoostTag && (t as HighestStatBoostTag).stat === stat) as HighestStatBoostTag;
+    if (highestStatBoost)
+      ret *= highestStatBoost.multiplier;
+
     return Math.floor(ret);
   }