diff --git a/src/app/partners/Lithostitched.ts b/src/app/partners/Lithostitched.ts
index 01b14f6f..675ee272 100644
--- a/src/app/partners/Lithostitched.ts
+++ b/src/app/partners/Lithostitched.ts
@@ -1,10 +1,11 @@
 import type { CollectionRegistry, ResourceType, SchemaRegistry } from '@mcschema/core'
 import { BooleanNode, Case, ChoiceNode, ListNode, Mod, NumberNode, ObjectNode, Opt, Reference as RawReference, StringNode as RawStringNode, Switch } from '@mcschema/core'
+import type { VersionId } from '../services/Schemas.js'
 
 
 const ID = 'lithostitched'
 
-export function initLithostitched(schemas: SchemaRegistry, collections: CollectionRegistry) {
+export function initLithostitched(schemas: SchemaRegistry, collections: CollectionRegistry, version: VersionId) {
 	const Reference = RawReference.bind(undefined, schemas)
 	const StringNode = RawStringNode.bind(undefined, collections)
 
@@ -69,6 +70,9 @@ export function initLithostitched(schemas: SchemaRegistry, collections: Collecti
 	collections.register(`${ID}:modifier_type`, [
 		'lithostitched:add_biome_spawns',
 		'lithostitched:add_features',
+		...(version === '1.20.5' || version === '1.21')
+			? ['lithostitched:add_pool_aliases']
+			: [],
 		'lithostitched:add_structure_set_entries',
 		'lithostitched:add_surface_rule',
 		'lithostitched:add_template_pool_elements',
@@ -91,7 +95,9 @@ export function initLithostitched(schemas: SchemaRegistry, collections: Collecti
 
 	schemas.register(`${ID}:worldgen_modifier`, Mod(ObjectNode({
 		type: StringNode({ validator: 'resource', params: { pool: `${ID}:modifier_type` as any } }),
-		predicate: Opt(Reference(`${ID}:modifier_predicate`)),
+		predicate: Mod(Opt(Reference(`${ID}:modifier_predicate`)), {
+			enabled: () => version !== '1.21',
+		}),
 		[Switch]: [{ push: 'type' }],
 		[Case]: {
 			'lithostitched:add_biome_spawns': {
@@ -114,6 +120,10 @@ export function initLithostitched(schemas: SchemaRegistry, collections: Collecti
 				features: Tag('$worldgen/configured_feature'),
 				step: StringNode({ enum: 'decoration_step' }),
 			},
+			'lithostitched:add_pool_aliases': {
+				structure: StringNode({ validator: 'resource', params: { pool: '$worldgen/structure' } }),
+				pool_aliases: Reference('pool_alias_binding'),
+			},
 			'lithostitched:add_structure_set_entries': {
 				structure_set: StringNode({ validator: 'resource', params: { pool: '$worldgen/structure_set' } }),
 				entries: ListNode(
diff --git a/src/app/partners/index.ts b/src/app/partners/index.ts
index 71ac72c8..f4dee4d7 100644
--- a/src/app/partners/index.ts
+++ b/src/app/partners/index.ts
@@ -1,4 +1,5 @@
 import type { CollectionRegistry, SchemaRegistry } from '@mcschema/core'
+import type { VersionId } from '../services/Schemas.js'
 import { initImmersiveWeathering } from './ImmersiveWeathering.js'
 import { initLithostitched } from './Lithostitched.js'
 import { initObsidian } from './Obsidian.js'
@@ -7,9 +8,9 @@ import { initOhTheTreesYoullGrow } from './OhTheTreesYoullGrow.js'
 export * from './ImmersiveWeathering.js'
 export * from './Lithostitched.js'
 
-export function initPartners(schemas: SchemaRegistry, collections: CollectionRegistry) {
+export function initPartners(schemas: SchemaRegistry, collections: CollectionRegistry, version: VersionId) {
 	initImmersiveWeathering(schemas, collections)
-	initLithostitched(schemas, collections)
+	initLithostitched(schemas, collections, version)
 	initObsidian(schemas, collections)
 	initOhTheTreesYoullGrow(schemas, collections)
 }
diff --git a/src/app/partners/locales/en.json b/src/app/partners/locales/en.json
index 0fac55f0..2c25112a 100644
--- a/src/app/partners/locales/en.json
+++ b/src/app/partners/locales/en.json
@@ -58,6 +58,7 @@
 
   "lithostitched:modifier_type.lithostitched:add_biome_spawns": "Add biome spawns",
   "lithostitched:modifier_type.lithostitched:add_features": "Add features",
+  "lithostitched:modifier_type.lithostitched:add_pool_aliases": "Add pool aliases",
   "lithostitched:modifier_type.lithostitched:add_structure_set_entries": "Add structure set entries",
   "lithostitched:modifier_type.lithostitched:add_surface_rule": "Add surface rule",
   "lithostitched:modifier_type.lithostitched:add_template_pool_elements": "Add template pool elements",
diff --git a/src/app/services/Schemas.ts b/src/app/services/Schemas.ts
index 46aec40e..206414c1 100644
--- a/src/app/services/Schemas.ts
+++ b/src/app/services/Schemas.ts
@@ -1,8 +1,8 @@
 import type { CollectionRegistry, INode, SchemaRegistry } from '@mcschema/core'
 import { ChoiceNode, DataModel, Reference, StringNode } from '@mcschema/core'
 import config from '../Config.js'
-import { initPartners } from '../partners/index.js'
 import { message } from '../Utils.js'
+import { initPartners } from '../partners/index.js'
 import { fetchData } from './DataFetcher.js'
 
 export const VersionIds = ['1.15', '1.16', '1.17', '1.18', '1.18.2', '1.19', '1.19.3', '1.19.4', '1.20', '1.20.2', '1.20.3', '1.20.5', '1.21'] as const
@@ -69,7 +69,7 @@ async function getVersion(id: VersionId): Promise<VersionData> {
 				const blockStates: BlockStateRegistry = {}
 				await fetchData(id, collections, blockStates)
 				const schemas = mcschema.getSchemas(collections)
-				initPartners(schemas, collections)
+				initPartners(schemas, collections, id)
 				Versions[id] = { collections, schemas, blockStates }
 				return Versions[id]
 			} catch (e) {