diff --git a/packages/txwrapper-core/src/core/construct/createSignedTx.spec.ts b/packages/txwrapper-core/src/core/construct/createSignedTx.spec.ts
index 36c79462..658e754f 100644
--- a/packages/txwrapper-core/src/core/construct/createSignedTx.spec.ts
+++ b/packages/txwrapper-core/src/core/construct/createSignedTx.spec.ts
@@ -4,6 +4,7 @@ import {
 	ASTAR_TEST_OPTIONS,
 	KUSAMA_TEST_OPTIONS,
 	signWithAlice,
+	signWithAliceAstar,
 	TEST_BASE_TX_INFO,
 	TEST_METHOD_ARGS,
 } from '@substrate/txwrapper-dev';
@@ -38,7 +39,7 @@ describe('createSignedTx', () => {
 			ASTAR_TEST_OPTIONS,
 		);
 		const signingPayload = createSigningPayload(unsigned, ASTAR_TEST_OPTIONS);
-		const signature = await signWithAlice(signingPayload);
+		const signature = await signWithAliceAstar(signingPayload);
 
 		const tx = createSignedTx(unsigned, signature, ASTAR_TEST_OPTIONS);
 		expect(tx).toBe(
diff --git a/packages/txwrapper-core/src/core/construct/getTxHash.spec.ts b/packages/txwrapper-core/src/core/construct/getTxHash.spec.ts
index f712d174..a24a04c9 100644
--- a/packages/txwrapper-core/src/core/construct/getTxHash.spec.ts
+++ b/packages/txwrapper-core/src/core/construct/getTxHash.spec.ts
@@ -4,6 +4,7 @@ import {
 	ASTAR_TEST_OPTIONS,
 	KUSAMA_TEST_OPTIONS,
 	signWithAlice,
+	signWithAliceAstar,
 	TEST_BASE_TX_INFO,
 	TEST_METHOD_ARGS,
 } from '@substrate/txwrapper-dev';
@@ -49,7 +50,7 @@ describe('getTxHash', () => {
 			unsigned,
 			ASTAR_TEST_OPTIONS,
 		);
-		const signature = await signWithAlice(signingPayload);
+		const signature = await signWithAliceAstar(signingPayload);
 		const signedTx = construct.signedTx(
 			unsigned,
 			signature,
@@ -58,7 +59,7 @@ describe('getTxHash', () => {
 
 		const txHash = getTxHash(signedTx);
 		expect(txHash).toBe(
-			'0x48598a4b920b83b931777088e6d1c9bcc1466518cb1ae0faa2a29553798e2f9c',
+			'0x1fc108525d6569889d53cbc092cba9c7ad0f59d668c60eff3447c774815d0485',
 		);
 	});
 });
diff --git a/packages/txwrapper-core/src/core/decode/decodeSignedTx.spec.ts b/packages/txwrapper-core/src/core/decode/decodeSignedTx.spec.ts
index 39f592b7..36621b8a 100644
--- a/packages/txwrapper-core/src/core/decode/decodeSignedTx.spec.ts
+++ b/packages/txwrapper-core/src/core/decode/decodeSignedTx.spec.ts
@@ -4,6 +4,7 @@ import {
 	ASTAR_TEST_OPTIONS,
 	KUSAMA_TEST_OPTIONS,
 	signWithAlice,
+	signWithAliceAstar,
 	TEST_BASE_TX_INFO,
 	TEST_METHOD_ARGS,
 } from '@substrate/txwrapper-dev';
@@ -69,7 +70,7 @@ describe('decodeSignedTx', () => {
 			unsigned,
 			ASTAR_TEST_OPTIONS,
 		);
-		const signature = await signWithAlice(signingPayload);
+		const signature = await signWithAliceAstar(signingPayload);
 		const signedTx = construct.signedTx(
 			unsigned,
 			signature,
diff --git a/packages/txwrapper-dev/src/util/index.ts b/packages/txwrapper-dev/src/util/index.ts
index 1cd9421d..df8e13c3 100644
--- a/packages/txwrapper-dev/src/util/index.ts
+++ b/packages/txwrapper-dev/src/util/index.ts
@@ -1,2 +1,3 @@
 export * from './knownChainProperties';
 export * from './signWithAlice';
+export * from './signWithAliceAstar';
diff --git a/packages/txwrapper-dev/src/util/signWithAliceAstar.ts b/packages/txwrapper-dev/src/util/signWithAliceAstar.ts
new file mode 100644
index 00000000..3ddca82e
--- /dev/null
+++ b/packages/txwrapper-dev/src/util/signWithAliceAstar.ts
@@ -0,0 +1,26 @@
+import { Keyring } from '@polkadot/api';
+import { cryptoWaitReady } from '@polkadot/util-crypto';
+
+import { ASTAR_TEST_OPTIONS } from '../constants';
+
+/**
+ * Sign a payload with seed `//Alice`.
+ */
+export async function signWithAliceAstar(
+	signingPayload: string,
+): Promise<`0x${string}`> {
+	// We're creating an Alice account that will sign the payload
+	// Wait for the promise to resolve async WASM
+	await cryptoWaitReady();
+	// Use ed25519 because it has deterministic signatures
+	const keyring = new Keyring({ type: 'ed25519' });
+	const alice = keyring.addFromUri('//Alice', { name: 'Alice default' });
+
+	const { signature } = ASTAR_TEST_OPTIONS.registry
+		.createType('ExtrinsicPayload', signingPayload, {
+			version: 4,
+		})
+		.sign(alice);
+
+	return signature;
+}