diff --git a/e2e/helper.ts b/e2e/helper.ts
index 59bed94d..8f0357da 100644
--- a/e2e/helper.ts
+++ b/e2e/helper.ts
@@ -58,7 +58,7 @@ const setupAll = async ({ endpoint, blockHash, mockSignatureHost, allowUnresolve
         now += 20000
         return now
       })
-      const inherents = new InherentProviders(setTimestamp, [new SetValidationData(tasks, 1)])
+      const inherents = new InherentProviders(setTimestamp, [new SetValidationData(tasks)])
 
       const chain = new Blockchain({
         api,
diff --git a/src/blockchain/inherents.ts b/src/blockchain/inherents.ts
index c70bcc02..6fcf6b29 100644
--- a/src/blockchain/inherents.ts
+++ b/src/blockchain/inherents.ts
@@ -81,11 +81,9 @@ export class InherentProviders implements InherentProvider {
 
 export class SetValidationData implements CreateInherents {
   readonly #tasks: TaskManager
-  readonly #expectedIndex: number
 
-  constructor(tasks: TaskManager, expectedIndex: number) {
+  constructor(tasks: TaskManager) {
     this.#tasks = tasks
-    this.#expectedIndex = expectedIndex
   }
 
   async createInherents(meta: DecoratedMeta, _timestamp: number, parent: Block): Promise<string[]> {
@@ -106,8 +104,16 @@ export class SetValidationData implements CreateInherents {
       // chain started with genesis, mock 1st validationData
       newData = MOCK_VALIDATION_DATA
     } else {
-      const method = meta.registry.createType<GenericExtrinsic>('GenericExtrinsic', extrinsics[this.#expectedIndex])
-      const extrinsic = method.args[0].toJSON() as typeof MOCK_VALIDATION_DATA
+      const validationDataExtrinsic = extrinsics.find((extrinsic) => {
+        const firstArg = meta.registry.createType<GenericExtrinsic>('GenericExtrinsic', extrinsic)?.args?.[0]
+        return firstArg && 'validationData' in firstArg
+      })
+      if (!validationDataExtrinsic) {
+        throw new Error('Missing validation data from block')
+      }
+      const extrinsic = meta.registry
+        .createType<GenericExtrinsic>('GenericExtrinsic', validationDataExtrinsic)
+        .args[0].toJSON() as typeof MOCK_VALIDATION_DATA
 
       const newEntries: [HexString, HexString][] = []
       const upgrade = await parentBlock.get(compactHex(meta.query.parachainSystem.pendingValidationCode()))
diff --git a/src/index.ts b/src/index.ts
index 87e03523..5e9dea87 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -62,7 +62,7 @@ export const setup = async (argv: Config) => {
   const setTimestamp = new SetTimestamp((newBlockNumber) => {
     return timestamp + (newBlockNumber - blockNumber) * 12000 // TODO: make this more flexible
   })
-  const inherents = new InherentProviders(setTimestamp, [new SetValidationData(tasks, 1)])
+  const inherents = new InherentProviders(setTimestamp, [new SetValidationData(tasks)])
 
   const chain = new Blockchain({
     api,