diff --git a/data/random-teams.ts b/data/random-teams.ts
index 203b45df69b9..eaa88fb5ec3d 100644
--- a/data/random-teams.ts
+++ b/data/random-teams.ts
@@ -2047,7 +2047,9 @@ export class RandomTeams {
 		// Picks `n` random pokemon--no repeats, even among formes
 		// Also need to either normalize for formes or select formes at random
 		// Unreleased are okay but no CAP
+		const last = [0, 151, 251, 386, 493, 649, 721, 807, 898, 1017][this.gen];
 
+		if (n <= 0 || n > last) throw new Error(`n must be a number between 1 and ${last} (got ${n})`);
 		if (requiredType && !this.dex.types.get(requiredType).exists) {
 			throw new Error(`"${requiredType}" is not a valid type.`);
 		}
@@ -2069,6 +2071,7 @@ export class RandomTeams {
 				if (minSourceGen && species.gen < minSourceGen) continue;
 				const num = species.num;
 				if (num <= 0 || pool.includes(num)) continue;
+				if (num > last) break;
 				pool.push(num);
 			}
 		} else {