diff --git a/src/field/pokemon.ts b/src/field/pokemon.ts
index 914e4bb8255..35fbb9133b3 100644
--- a/src/field/pokemon.ts
+++ b/src/field/pokemon.ts
@@ -357,7 +357,7 @@ export default abstract class Pokemon extends Phaser.GameObjects.Container {
   public fusionCustomPokemonData: CustomPokemonData | null;
   public fusionTeraType: PokemonType;
 
-  public customPokemonData: CustomPokemonData = new CustomPokemonData;
+  public customPokemonData: CustomPokemonData = new CustomPokemonData();
 
   /* Pokemon data types, in vaguely decreasing order of precedence */