diff --git a/src/lib/combat_achievements/elite.ts b/src/lib/combat_achievements/elite.ts
index 982ba3cc28..175a9fe2a5 100644
--- a/src/lib/combat_achievements/elite.ts
+++ b/src/lib/combat_achievements/elite.ts
@@ -1521,7 +1521,8 @@ export const eliteCombatAchievements: CombatAchievement[] = [
 		rng: {
 			chancePerKill: 12,
 			hasChance: (data, _user, index) =>
-				data.type === 'Colosseum' && (!data.diedAt || (Array.isArray(data.diedAt) && data.diedAt[index]! > 7))
+				data.type === 'Colosseum' &&
+				(!data.diedAt || (Array.isArray(data.diedAt) && (!data.diedAt[index] || data.diedAt[index] > 7)))
 		}
 	},
 	{
diff --git a/src/lib/combat_achievements/master.ts b/src/lib/combat_achievements/master.ts
index e80e94c6ee..7576c65b87 100644
--- a/src/lib/combat_achievements/master.ts
+++ b/src/lib/combat_achievements/master.ts
@@ -1472,7 +1472,8 @@ export const masterCombatAchievements: CombatAchievement[] = [
 		rng: {
 			chancePerKill: 15,
 			hasChance: (data, _user, index) =>
-				data.type === 'Colosseum' && (!data.diedAt || (Array.isArray(data.diedAt) && data.diedAt[index]! > 11))
+				data.type === 'Colosseum' &&
+				(!data.diedAt || (Array.isArray(data.diedAt) && (!data.diedAt[index] || data.diedAt[index] > 11)))
 		}
 	},
 	{