diff --git a/data/rulesets.ts b/data/rulesets.ts
index 2c74a67180..c95bea0b04 100644
--- a/data/rulesets.ts
+++ b/data/rulesets.ts
@@ -103,7 +103,7 @@ export const Rulesets: import('../sim/dex-formats').FormatDataTable = {
 		name: 'NatDex Mod',
 		desc: "Mechanics for National Dex formats",
 		ruleset: [
-			'+Unobtainable', '+Past', 'Sketch Post-Gen 7 Moves', 'Min Source Gen = 1',
+			'+Unobtainable', '+Past', 'Sketch Post-Gen 7 Moves',
 		],
 		onValidateSet(set) {
 			const species = this.dex.species.get(set.species);
diff --git a/sim/dex-formats.ts b/sim/dex-formats.ts
index 4ff161df4a..0d17651742 100644
--- a/sim/dex-formats.ts
+++ b/sim/dex-formats.ts
@@ -230,8 +230,8 @@ export class RuleTable extends Map<string, string> {
 		this.evLimit = Number(this.valueRules.get('evlimit'));
 		if (isNaN(this.evLimit)) this.evLimit = null;
 		if (!this.minSourceGen) {
-			if (format.gen >= 9 && this.has('obtainable') && !this.has('+past')) {
-				this.minSourceGen = format.gen;
+			if (dex.gen >= 9 && this.has('obtainable') && !this.has('+past')) {
+				this.minSourceGen = dex.gen;
 			} else {
 				this.minSourceGen = 1;
 			}