diff --git a/__tests__/main.test.ts b/__tests__/main.test.ts
index ef905b4..c6b37c2 100644
--- a/__tests__/main.test.ts
+++ b/__tests__/main.test.ts
@@ -4,6 +4,7 @@ import * as process from 'process'
 import * as cp from 'child_process'
 import * as path from 'path'
 import {test} from '@jest/globals'
+import {expect} from '@jest/globals'
 
 test('test sha256', async () => {
   console.info(hashHex('this is content'))
@@ -36,3 +37,25 @@ test('test runs', () => {
   }
   console.info(cp.execFileSync(np, [ip], options).toString())
 })
+
+test('test runs - hash is consistent', () => {
+  process.env['INPUT_WORKDIR'] = './'
+  process.env['INPUT_PATTERNS'] = '**/*.ts\n**/package-lock.json'
+  process.env['INPUT_GITIGNORE'] = 'true'
+  const np = process.execPath
+  const ip = path.join(__dirname, '..', 'lib', 'main.js')
+  const options: cp.ExecFileSyncOptions = {
+    env: process.env
+  }
+  const results: string[] = []
+  for (let i = 0; i < 5; i++) {
+    results.push(cp.execFileSync(np, [ip], options).toString())
+  }
+  // Extract hash from output and check all are the same
+  const hashes = results.map(output => {
+    const match = output.match(/Hash: ([a-fA-F0-9]+)/)
+    return match ? match[1] : null
+  })
+  expect(new Set(hashes).size).toBe(1)
+  console.info('All hashes:', hashes)
+})