diff --git a/src/executor.test.ts b/src/executor.test.ts
index cd84fe47..850ab1d4 100644
--- a/src/executor.test.ts
+++ b/src/executor.test.ts
@@ -11,13 +11,16 @@ import {
   hrmpIngressChannelIndex,
   upgradeGoAheadSignal,
 } from './utils/proof'
-import { calculateStateRoot, createProof, decodeProof, getRuntimeVersion } from './executor'
+import { calculateStateRoot, createProof, decodeProof, getAuraSlotDuration, getRuntimeVersion } from './executor'
+
+const getCode = () => {
+  const code = String(readFileSync(path.join(__dirname, '../e2e/blobs/acala-runtime-2101.txt'))).trim()
+  expect(code.length).toBeGreaterThan(2)
+  return code as HexString
+}
 
 describe('wasm', () => {
   it('get runtime version from wasm runtime', async () => {
-    const code = String(readFileSync(path.join(__dirname, '../e2e/blobs/acala-runtime-2101.txt'))).trim()
-    expect(code.length).toBeGreaterThan(2)
-
     const expectedRuntimeVersion = {
       specName: 'acala',
       implName: 'acala',
@@ -43,7 +46,7 @@ describe('wasm', () => {
       stateVersion: 0,
     }
 
-    expect(await getRuntimeVersion(code as HexString)).toMatchObject(expectedRuntimeVersion)
+    expect(await getRuntimeVersion(getCode())).toMatchObject(expectedRuntimeVersion)
   })
 
   it('calculate state root', async () => {
@@ -149,4 +152,9 @@ describe('wasm', () => {
     expect(decoded).toMatchSnapshot()
     expect(decoded[upgradeKey]).toBe('0x01')
   })
+
+  it('get aura slot duration', async () => {
+    const slotDuration = await getAuraSlotDuration(getCode(), new TypeRegistry())
+    expect(slotDuration).eq(12000)
+  })
 })
diff --git a/src/executor.ts b/src/executor.ts
index f59ae2c1..6e6b98c3 100644
--- a/src/executor.ts
+++ b/src/executor.ts
@@ -12,6 +12,7 @@ import {
 global.WebSocket = WebSocket
 
 import { Block } from './blockchain/block'
+import { Registry } from '@polkadot/types-codec/types'
 import {
   calculate_state_root,
   create_proof,
@@ -21,7 +22,11 @@ import {
 } from '@acala-network/chopsticks-executor'
 import { defaultLogger, truncate, truncateStorageDiff } from './logger'
 
-const logger = defaultLogger.child({ name: 'executor' })
+interface JsCallback {
+  getStorage: (key: HexString) => Promise<string | undefined>
+  getPrefixKeys: (key: HexString) => Promise<string[]>
+  getNextKey: (key: HexString) => Promise<string | undefined>
+}
 
 export type RuntimeVersion = {
   specName: string
@@ -34,6 +39,8 @@ export type RuntimeVersion = {
   stateVersion: number
 }
 
+const logger = defaultLogger.child({ name: 'executor' })
+
 export const getRuntimeVersion = async (code: HexString): Promise<RuntimeVersion> => {
   return get_runtime_version(code).then((version) => {
     version.specName = hexToString(version.specName)
@@ -76,7 +83,7 @@ export const runTask = async (
     mockSignatureHost: boolean
     allowUnresolvedImports: boolean
   },
-  callback: JsCallback
+  callback: JsCallback = emptyTaskHandler
 ) => {
   logger.trace({ task: { ...task, wasm: truncate(task.wasm) } }, 'taskRun')
   const response = await run_task(task, callback)
@@ -91,12 +98,6 @@ export const runTask = async (
   return response
 }
 
-interface JsCallback {
-  getStorage: (key: HexString) => Promise<string | undefined>
-  getPrefixKeys: (key: HexString) => Promise<string[]>
-  getNextKey: (key: HexString) => Promise<string | undefined>
-}
-
 export const taskHandler = (block: Block): JsCallback => {
   return {
     getStorage: async function (key: HexString) {
@@ -111,3 +112,29 @@ export const taskHandler = (block: Block): JsCallback => {
     },
   }
 }
+
+export const emptyTaskHandler = {
+  getStorage: async function (_key: HexString) {
+    throw new Error('Method not implemented')
+  },
+  getPrefixKeys: async function (_key: HexString) {
+    throw new Error('Method not implemented')
+  },
+  getNextKey: async function (_key: HexString) {
+    throw new Error('Method not implemented')
+  },
+}
+
+export const getAuraSlotDuration = async (wasm: HexString, registry: Registry): Promise<number> => {
+  const result = await runTask({
+    wasm,
+    calls: [['AuraApi_slot_duration', '0x']],
+    storage: [],
+    mockSignatureHost: false,
+    allowUnresolvedImports: false,
+  })
+
+  if (!result.Call) throw new Error(result.Error)
+  const slotDuration = registry.createType('u64', hexToU8a(result.Call.result)).toNumber()
+  return slotDuration
+}
diff --git a/src/utils/time-travel.ts b/src/utils/time-travel.ts
index 0772692f..bb85afd7 100644
--- a/src/utils/time-travel.ts
+++ b/src/utils/time-travel.ts
@@ -4,6 +4,7 @@ import { Slot } from '@polkadot/types/interfaces'
 
 import { Blockchain } from '../blockchain'
 import { compactHex } from '.'
+import { getAuraSlotDuration } from '../executor'
 import { setStorage } from './set-storage'
 
 export const getCurrentSlot = async (chain: Blockchain) => {
@@ -25,7 +26,7 @@ export const getSlotDuration = async (chain: Blockchain) => {
   const meta = await chain.head.meta
   return meta.consts.babe
     ? (meta.consts.babe.expectedBlockTime as any as BN).toNumber()
-    : (meta.consts.timestamp.minimumPeriod as any as BN).toNumber() * 2
+    : getAuraSlotDuration(await chain.head.wasm, meta.registry)
 }
 
 export const timeTravel = async (chain: Blockchain, timestamp: number) => {