diff --git a/CHANGELOG.md b/CHANGELOG.md
index a52752a..522c71a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,21 @@
 # Changelog
 
+## 0.12.1
+
+### Fixed
+
+- **All three built-in network genesis hashes refreshed after chain resets.** `PASEO_ASSET_HUB`, `PREVIEWNET`, and `PREVIEWNET_ASSET_HUB` all pinned genesis values from earlier deployments of those chains. Each was verified dead against live RPC via `chain_getBlockHash(0)`:
+
+  | Constant | Was | Now |
+  |---|---|---|
+  | `PASEO_ASSET_HUB` | `0xbf0488…ef19f` | `0x23e730eb1c6fecae09c917439a5038cb6122d0d48980e8b9bbf0ff56f94a2ca6` |
+  | `PREVIEWNET` | `0x477dd8…12525` | `0x8c27ddf678c2ae9bef0efebfc485a9309f3d735c6d3fbb8d947afc3ace0e80f4` |
+  | `PREVIEWNET_ASSET_HUB` | `0x860d75…c7867c` | `0x4d11c803cc6921429e3876638977ad006ea1bba8cd3976a0bca2f164e7026210` |
+
+### Internal
+
+- The chain-feature integration test now reads the expected genesis from `PASEO_ASSET_HUB.genesisHash` instead of repeating the literal, so the next reset is a one-line change in `src/networks.ts`.
+
 ## 0.12.0
 
 ### Breaking changes
diff --git a/forum-post.md b/forum-post.md
index d291a34..ffe4257 100644
--- a/forum-post.md
+++ b/forum-post.md
@@ -749,3 +749,29 @@ Alias errors moved out of `RequestCredentialsErr` into their own enum (`RingNotF
 1. Upgrade to `0.12.0` and move your product side to `@parity/truapi@^0.6.0` or `@novasamatech/host-api-wrapper@^0.9.1` in the same commit.
 2. Through the wrapper, nothing else. Hand-built requests: wrap indices in `derivationIndexOf()` and adjust the three shapes above.
 3. If your fixtures still pass `chain:`, see 0.10.0 — it is silently ignored, so any `rpcUrl` override you set is being dropped.
+
+---
+
+# host-api-test-sdk 0.12.1
+
+One fix. Drop-in upgrade from `0.12.0`.
+
+## Fixed
+
+- **All three built-in network genesis hashes refreshed after chain resets.** `PASEO_ASSET_HUB`, `PREVIEWNET`, and `PREVIEWNET_ASSET_HUB` were all pinned to genesis values from earlier deployments of those chains, verified dead against live RPC:
+
+  | Constant | Was | Now |
+  |---|---|---|
+  | `PASEO_ASSET_HUB` | `0xbf0488…ef19f` | `0x23e730eb1c6fecae09c917439a5038cb6122d0d48980e8b9bbf0ff56f94a2ca6` |
+  | `PREVIEWNET` | `0x477dd8…12525` | `0x8c27ddf678c2ae9bef0efebfc485a9309f3d735c6d3fbb8d947afc3ace0e80f4` |
+  | `PREVIEWNET_ASSET_HUB` | `0x860d75…c7867c` | `0x4d11c803cc6921429e3876638977ad006ea1bba8cd3976a0bca2f164e7026210` |
+
+The host routes each connection request to a network by genesis hash, so a stale pin means the host does not recognise the chain your product is asking for. The symptom is the product stuck at `connection-status: "connecting"` until the test times out, with a reachable RPC endpoint and nothing obviously wrong in the logs.
+
+One thing worth calling out: before this release the pins were wrong but *consistent*. A test host and a set of descriptors both generated against the same dead chain agree with each other perfectly, so a suite can be green while connected to a chain that no longer exists. If your e2e went green across one of these resets without you touching anything, that is what happened.
+
+## What you need to do
+
+- Upgrade to `0.12.1`. If you use the built-in network configs, that is the whole change — the correct hashes come with the upgrade.
+- If you hard-coded any of the three old hashes in your own `NetworkConfig` or in test assertions, update them. Better still, read them off the exported config (`PASEO_ASSET_HUB.genesisHash`) so the next reset costs you nothing.
+- These chains reset periodically. Treat a genesis literal in your own repo as something that will go stale, not as a constant.
diff --git a/package.json b/package.json
index 73e7558..f3b98c5 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@parity/host-api-test-sdk",
-  "version": "0.12.0",
+  "version": "0.12.1",
   "description": "Lightweight test host for Spektr product E2E testing — embeds dapps with auto-signing dev accounts, no Docker needed",
   "license": "MIT",
   "repository": {
diff --git a/src/networks.ts b/src/networks.ts
index 7a54a98..b81af5e 100644
--- a/src/networks.ts
+++ b/src/networks.ts
@@ -3,7 +3,7 @@ import type { NetworkConfig, HexString } from './types.js';
 export const PASEO_ASSET_HUB: NetworkConfig = {
   id: 'paseo-asset-hub',
   name: 'Paseo Asset Hub',
-  genesisHash: '0xbf0488dbe9daa1de1c08c5f743e26fdc2a4ecd74cf87dd1b4b1eeb99ae4ef19f' as HexString,
+  genesisHash: '0x23e730eb1c6fecae09c917439a5038cb6122d0d48980e8b9bbf0ff56f94a2ca6' as HexString,
   rpcUrl: 'wss://paseo-asset-hub-next-rpc.polkadot.io',
   tokenSymbol: 'PAS',
   tokenDecimals: 10,
@@ -12,7 +12,7 @@ export const PASEO_ASSET_HUB: NetworkConfig = {
 export const PREVIEWNET: NetworkConfig = {
   id: 'previewnet',
   name: 'Previewnet',
-  genesisHash: '0x477dd87a881ae4d8072030073406be59de42215b4a7c4c337ce1a25727912525' as HexString,
+  genesisHash: '0x8c27ddf678c2ae9bef0efebfc485a9309f3d735c6d3fbb8d947afc3ace0e80f4' as HexString,
   rpcUrl: 'wss://previewnet.substrate.dev/relay/alice',
   tokenSymbol: 'UNIT',
   tokenDecimals: 12,
@@ -21,7 +21,7 @@ export const PREVIEWNET: NetworkConfig = {
 export const PREVIEWNET_ASSET_HUB: NetworkConfig = {
   id: 'previewnet-asset-hub',
   name: 'Previewnet Asset Hub',
-  genesisHash: '0x860d75a890388e2ad02c54aa451264d04af89765773a51cd56868b4293c7867c' as HexString,
+  genesisHash: '0x4d11c803cc6921429e3876638977ad006ea1bba8cd3976a0bca2f164e7026210' as HexString,
   rpcUrl: 'wss://previewnet.substrate.dev/asset-hub',
   tokenSymbol: 'UNIT',
   tokenDecimals: 12,
diff --git a/test/integration.spec.ts b/test/integration.spec.ts
index 6d0d925..1e27c0f 100644
--- a/test/integration.spec.ts
+++ b/test/integration.spec.ts
@@ -12,7 +12,7 @@ import { test, expect } from '@playwright/test';
 import { Keyring } from '@polkadot/keyring';
 import { cryptoWaitReady, sr25519Verify } from '@polkadot/util-crypto';
 import { compactFromU8a, hexToU8a, u8aToHex } from '@polkadot/util';
-import { createTestHostServer } from '../dist/index.js';
+import { createTestHostServer, PASEO_ASSET_HUB } from '../dist/index.js';
 import { loadHost, serveProduct } from './support';
 
 // ── Helpers ─────────────────────────────────────────────────────────
@@ -1239,10 +1239,11 @@ test.describe('Feature check', () => {
     try {
       const product = await loadHostAndProduct(page, host.url, productServer.url);
 
-      // Default chain is PASEO_ASSET_HUB
-      const result = await product.evaluate(() =>
-        window.__TEST_PRODUCT__.featureSupported('Chain',
-          '0xbf0488dbe9daa1de1c08c5f743e26fdc2a4ecd74cf87dd1b4b1eeb99ae4ef19f'));
+      // Default chain is PASEO_ASSET_HUB. Read the genesis from the config
+      // rather than repeating the literal, so a chain reset only needs one edit.
+      const result = await product.evaluate((genesis: string) =>
+        window.__TEST_PRODUCT__.featureSupported('Chain', genesis),
+        PASEO_ASSET_HUB.genesisHash);
       expect(result.ok).toBe(true);
       expect(result.supported).toBe(true);
     } finally {