diff --git a/config/formats.ts b/config/formats.ts
index 38f10829d3a7..37549c0dabbf 100644
--- a/config/formats.ts
+++ b/config/formats.ts
@@ -1760,13 +1760,11 @@ export const Formats: import('../sim/dex-formats').FormatList = [
 					return [this.terastallized];
 				}
 				const types = this.battle.runEvent('Type', this, null, null, this.types);
+				if (!types.length) types.push(this.battle.gen >= 5 ? 'Normal' : '???');
 				if (!excludeAdded && this.addedType) return types.concat(this.addedType);
 				const addTeraType = this.m.thirdType;
-				if (types.length) {
-					if (addTeraType) return Array.from(new Set([...types, addTeraType]));
-					return types;
-				}
-				return [this.battle.gen >= 5 ? 'Normal' : '???'];
+				if (addTeraType) return Array.from(new Set([...types, addTeraType]));
+				return types;
 			},
 			runEffectiveness(move) {
 				if ((this.terastallized || this.m.thirdType) && move.type === 'Stellar') return 1;
diff --git a/sim/pokemon.ts b/sim/pokemon.ts
index bca968b7ec95..9a9bd5da2e78 100644
--- a/sim/pokemon.ts
+++ b/sim/pokemon.ts
@@ -2043,9 +2043,9 @@ export class Pokemon {
 			return [this.terastallized];
 		}
 		const types = this.battle.runEvent('Type', this, null, null, this.types);
+		if (!types.length) types.push(this.battle.gen >= 5 ? 'Normal' : '???');
 		if (!excludeAdded && this.addedType) return types.concat(this.addedType);
-		if (types.length) return types;
-		return [this.battle.gen >= 5 ? 'Normal' : '???'];
+		return types;
 	}
 
 	isGrounded(negateImmunity = false) {
diff --git a/test/sim/moves/roost.js b/test/sim/moves/roost.js
index 5151e241aee6..690989a124b9 100644
--- a/test/sim/moves/roost.js
+++ b/test/sim/moves/roost.js
@@ -73,7 +73,13 @@ describe('Roost', function () {
 	it('should treat a pure Flying pokémon as Normal type', function () {
 		battle = common.createBattle();
 		battle.setPlayer('p1', {team: [{species: "Tornadus", item: 'focussash', ability: 'prankster', moves: ['roost']}]});
-		battle.setPlayer('p2', {team: [{species: "Gastly", item: 'laggingtail', ability: 'levitate', moves: ['astonish']}]});
+		battle.setPlayer('p2', {team: [{species: "Gastly", item: 'laggingtail', ability: 'levitate', moves: ['astonish', 'trickortreat']}]});
+		battle.makeChoices('move roost', 'move astonish');
+		battle.makeChoices('move roost', 'move astonish');
+		assert.equal(battle.p1.active[0].hp, battle.p1.active[0].maxhp); // Immune to Astonish
+
+		// Ensure that it also replaces the Flying type with Normal even when there is an added type
+		battle.makeChoices('move roost', 'move trickortreat');
 		battle.makeChoices('move roost', 'move astonish');
 		battle.makeChoices('move roost', 'move astonish');
 		assert.equal(battle.p1.active[0].hp, battle.p1.active[0].maxhp); // Immune to Astonish