diff --git a/src/data/pokemon-evolutions.ts b/src/data/pokemon-evolutions.ts
index e7baf608b97..e29a4c16c29 100644
--- a/src/data/pokemon-evolutions.ts
+++ b/src/data/pokemon-evolutions.ts
@@ -64,21 +64,21 @@ export class SpeciesFormEvolution {
   public level: integer;
   public item: EvolutionItem | null;
   public condition: SpeciesEvolutionCondition | null;
-  public wildDelay: SpeciesWildEvolutionDelay | null;
+  public wildDelay: SpeciesWildEvolutionDelay;
 
-  constructor(speciesId: Species, preFormKey: string | null, evoFormKey: string | null, level: integer, item: EvolutionItem | null, condition: SpeciesEvolutionCondition | null, wildDelay?: SpeciesWildEvolutionDelay | null) {
+  constructor(speciesId: Species, preFormKey: string | null, evoFormKey: string | null, level: integer, item: EvolutionItem | null, condition: SpeciesEvolutionCondition | null, wildDelay?: SpeciesWildEvolutionDelay) {
     this.speciesId = speciesId;
     this.preFormKey = preFormKey;
     this.evoFormKey = evoFormKey;
     this.level = level;
     this.item = item || EvolutionItem.NONE;
     this.condition = condition;
-    this.wildDelay = wildDelay!; // TODO: is this bang correct?
+    this.wildDelay = wildDelay ?? SpeciesWildEvolutionDelay.NONE;
   }
 }
 
 export class SpeciesEvolution extends SpeciesFormEvolution {
-  constructor(speciesId: Species, level: integer, item: EvolutionItem | null, condition: SpeciesEvolutionCondition | null, wildDelay?: SpeciesWildEvolutionDelay | null) {
+  constructor(speciesId: Species, level: integer, item: EvolutionItem | null, condition: SpeciesEvolutionCondition | null, wildDelay?: SpeciesWildEvolutionDelay) {
     super(speciesId, null, null, level, item, condition, wildDelay);
   }
 }
@@ -400,8 +400,8 @@ export const pokemonEvolutions: PokemonEvolutions = {
     new SpeciesEvolution(Species.LINOONE, 20, null, null)
   ],
   [Species.WURMPLE]: [
-    new SpeciesEvolution(Species.SILCOON, 7, null, new SpeciesEvolutionCondition(p => p.scene.arena.getTimeOfDay() === TimeOfDay.DAWN || p.scene.arena.getTimeOfDay() === TimeOfDay.DAY), null),
-    new SpeciesEvolution(Species.CASCOON, 7, null, new SpeciesEvolutionCondition(p => p.scene.arena.getTimeOfDay() === TimeOfDay.DUSK || p.scene.arena.getTimeOfDay() === TimeOfDay.NIGHT), null)
+    new SpeciesEvolution(Species.SILCOON, 7, null, new SpeciesEvolutionCondition(p => p.scene.arena.getTimeOfDay() === TimeOfDay.DAWN || p.scene.arena.getTimeOfDay() === TimeOfDay.DAY)),
+    new SpeciesEvolution(Species.CASCOON, 7, null, new SpeciesEvolutionCondition(p => p.scene.arena.getTimeOfDay() === TimeOfDay.DUSK || p.scene.arena.getTimeOfDay() === TimeOfDay.NIGHT))
   ],
   [Species.SILCOON]: [
     new SpeciesEvolution(Species.BEAUTIFLY, 10, null, null)
@@ -945,7 +945,7 @@ export const pokemonEvolutions: PokemonEvolutions = {
     new SpeciesEvolution(Species.SHIINOTIC, 24, null, null)
   ],
   [Species.SALANDIT]: [
-    new SpeciesEvolution(Species.SALAZZLE, 33, null, new SpeciesEvolutionCondition(p => p.gender === Gender.FEMALE, p => p.gender = Gender.FEMALE), null)
+    new SpeciesEvolution(Species.SALAZZLE, 33, null, new SpeciesEvolutionCondition(p => p.gender === Gender.FEMALE, p => p.gender = Gender.FEMALE))
   ],
   [Species.STUFFUL]: [
     new SpeciesEvolution(Species.BEWEAR, 27, null, null)
@@ -969,8 +969,8 @@ export const pokemonEvolutions: PokemonEvolutions = {
     new SpeciesEvolution(Species.COSMOEM, 43, null, null)
   ],
   [Species.COSMOEM]: [
-    new SpeciesEvolution(Species.SOLGALEO, 53, null, new SpeciesEvolutionCondition(p => p.scene.arena.getTimeOfDay() === TimeOfDay.DAY), null),
-    new SpeciesEvolution(Species.LUNALA, 53, null, new SpeciesEvolutionCondition(p => p.scene.arena.getTimeOfDay() === TimeOfDay.NIGHT), null)
+    new SpeciesEvolution(Species.SOLGALEO, 53, null, new SpeciesEvolutionCondition(p => p.scene.arena.getTimeOfDay() === TimeOfDay.DAY)),
+    new SpeciesEvolution(Species.LUNALA, 53, null, new SpeciesEvolutionCondition(p => p.scene.arena.getTimeOfDay() === TimeOfDay.NIGHT))
   ],
   [Species.MELTAN]: [
     new SpeciesEvolution(Species.MELMETAL, 48, null, null)
@@ -1406,9 +1406,9 @@ export const pokemonEvolutions: PokemonEvolutions = {
     new SpeciesEvolution(Species.CRABOMINABLE, 1, EvolutionItem.ICE_STONE, null, SpeciesWildEvolutionDelay.LONG)
   ],
   [Species.ROCKRUFF]: [
-    new SpeciesFormEvolution(Species.LYCANROC, "", "midday", 25, null, new SpeciesEvolutionCondition(p => (p.scene.arena.getTimeOfDay() === TimeOfDay.DAWN || p.scene.arena.getTimeOfDay() === TimeOfDay.DAY) && (p.formIndex === 0)), null),
-    new SpeciesFormEvolution(Species.LYCANROC, "", "dusk", 25, null, new SpeciesEvolutionCondition(p =>  p.formIndex === 1), null),
-    new SpeciesFormEvolution(Species.LYCANROC, "", "midnight", 25, null, new SpeciesEvolutionCondition(p => (p.scene.arena.getTimeOfDay() === TimeOfDay.DUSK || p.scene.arena.getTimeOfDay() === TimeOfDay.NIGHT) && (p.formIndex === 0)), null)
+    new SpeciesFormEvolution(Species.LYCANROC, "", "midday", 25, null, new SpeciesEvolutionCondition(p => (p.scene.arena.getTimeOfDay() === TimeOfDay.DAWN || p.scene.arena.getTimeOfDay() === TimeOfDay.DAY) && (p.formIndex === 0))),
+    new SpeciesFormEvolution(Species.LYCANROC, "", "dusk", 25, null, new SpeciesEvolutionCondition(p =>  p.formIndex === 1)),
+    new SpeciesFormEvolution(Species.LYCANROC, "", "midnight", 25, null, new SpeciesEvolutionCondition(p => (p.scene.arena.getTimeOfDay() === TimeOfDay.DUSK || p.scene.arena.getTimeOfDay() === TimeOfDay.NIGHT) && (p.formIndex === 0)))
   ],
   [Species.STEENEE]: [
     new SpeciesEvolution(Species.TSAREENA, 28, null, new SpeciesEvolutionCondition(p => p.moveset.filter(m => m?.moveId === Moves.STOMP).length > 0), SpeciesWildEvolutionDelay.LONG)
diff --git a/src/test/evolution.test.ts b/src/test/evolution.test.ts
index c8ebffa6119..b1764a67ad7 100644
--- a/src/test/evolution.test.ts
+++ b/src/test/evolution.test.ts
@@ -1,4 +1,4 @@
-import { pokemonEvolutions } from "#app/data/pokemon-evolutions.js";
+import { pokemonEvolutions, SpeciesFormEvolution, SpeciesWildEvolutionDelay } from "#app/data/pokemon-evolutions.js";
 import { Abilities } from "#app/enums/abilities.js";
 import { Species } from "#app/enums/species.js";
 import GameManager from "#test/utils/gameManager";
@@ -83,4 +83,10 @@ describe("Evolution", () => {
     expect(ninjask.abilityIndex).toBe(2);
     expect(shedinja.abilityIndex).toBe(1);
   }, TIMEOUT);
+
+  it("should set wild delay to NONE by default", () => {
+    const speciesFormEvo = new SpeciesFormEvolution(Species.ABRA, null, null, 1000, null, null);
+
+    expect(speciesFormEvo.wildDelay).toBe(SpeciesWildEvolutionDelay.NONE);
+  });
 });