diff --git a/README.md b/README.md
index daff6fb..24bae0e 100644
--- a/README.md
+++ b/README.md
@@ -6,7 +6,11 @@ Install pnpm package manager.
 
 ### `version`
 
-**Required** Version of pnpm to install. It supports npm versioning scheme, it could be an exact version (such as `6.24.1`), or a version range (such as `6`, `6.x.x`, `6.24.x`, `^6.24.1`, `*`, etc.), or `latest`.
+Version of pnpm to install.
+
+**Optional** when there is a [`packageManager` field in the `package.json`](https://nodejs.org/api/corepack.html).
+
+otherwise, this field is **required** It supports npm versioning scheme, it could be an exact version (such as `6.24.1`), or a version range (such as `6`, `6.x.x`, `6.24.x`, `^6.24.1`, `*`, etc.), or `latest`.
 
 ### `dest`
 
diff --git a/dist/index.js b/dist/index.js
index b1e96f9..ca73795 100644
Binary files a/dist/index.js and b/dist/index.js differ
diff --git a/package.json b/package.json
index c41a3de..3b688ef 100644
--- a/package.json
+++ b/package.json
@@ -8,21 +8,21 @@
   },
   "dependencies": {
     "@actions/core": "^1.6.0",
-    "@pnpm/fetch": "^4.2.4",
+    "@pnpm/fetch": "^4.2.5",
     "@pnpm/logger": "^4.0.0",
     "@types/expand-tilde": "^2.0.0",
     "@types/fs-extra": "^9.0.13",
     "@types/js-yaml": "^4.0.5",
     "@types/node": "^14.18.10",
-    "@types/node-fetch": "^2.5.12",
+    "@types/node-fetch": "^2.6.1",
     "ajv": "^6.12.6",
     "expand-tilde": "^2.0.2",
-    "fs-extra": "^9.1.0",
+    "fs-extra": "^10.0.0",
     "js-yaml": "^4.1.0"
   },
   "devDependencies": {
     "@ts-schema-autogen/cli": "^0.1.2",
-    "@vercel/ncc": "^0.27.0",
+    "@vercel/ncc": "^0.33.3",
     "typescript": "^4.5.5"
   }
 }
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 10d69d5..3d2d5b1 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -2,38 +2,38 @@ lockfileVersion: 5.3
 
 specifiers:
   '@actions/core': ^1.6.0
-  '@pnpm/fetch': ^4.2.4
+  '@pnpm/fetch': ^4.2.5
   '@pnpm/logger': ^4.0.0
   '@ts-schema-autogen/cli': ^0.1.2
   '@types/expand-tilde': ^2.0.0
   '@types/fs-extra': ^9.0.13
   '@types/js-yaml': ^4.0.5
   '@types/node': ^14.18.10
-  '@types/node-fetch': ^2.5.12
-  '@vercel/ncc': ^0.27.0
+  '@types/node-fetch': ^2.6.1
+  '@vercel/ncc': ^0.33.3
   ajv: ^6.12.6
   expand-tilde: ^2.0.2
-  fs-extra: ^9.1.0
+  fs-extra: ^10.0.0
   js-yaml: ^4.1.0
   typescript: ^4.5.5
 
 dependencies:
   '@actions/core': 1.6.0
-  '@pnpm/fetch': 4.2.4_@pnpm+logger@4.0.0
+  '@pnpm/fetch': 4.2.5_@pnpm+logger@4.0.0
   '@pnpm/logger': 4.0.0
   '@types/expand-tilde': 2.0.0
   '@types/fs-extra': 9.0.13
   '@types/js-yaml': 4.0.5
   '@types/node': 14.18.10
-  '@types/node-fetch': 2.5.12
+  '@types/node-fetch': 2.6.1
   ajv: 6.12.6
   expand-tilde: 2.0.2
-  fs-extra: 9.1.0
+  fs-extra: 10.0.0
   js-yaml: 4.1.0
 
 devDependencies:
   '@ts-schema-autogen/cli': 0.1.2
-  '@vercel/ncc': 0.27.0
+  '@vercel/ncc': 0.33.3
   typescript: 4.5.5
 
 packages:
@@ -50,23 +50,23 @@ packages:
       tunnel: 0.0.6
     dev: false
 
-  /@pnpm/core-loggers/6.1.3_@pnpm+logger@4.0.0:
-    resolution: {integrity: sha512-X3mEhYz+8DKy4Xxbr24tGK9jPD+1AIhigGiJ9Fd0q+ywHXQ6ECSFyGGikKEAlBQIKVJxG788Mi0Zo13TU91fEQ==}
+  /@pnpm/core-loggers/6.1.4_@pnpm+logger@4.0.0:
+    resolution: {integrity: sha512-vF4Qc8E8e4uCGbVc7USCgqxrRe4eZsz8XEuCTUy6asZFVnNnRY/N1vJaVG3hti/UYKI/1si1dJYibppXhgTimA==}
     engines: {node: '>=12.17'}
     peerDependencies:
       '@pnpm/logger': ^4.0.0
     dependencies:
       '@pnpm/logger': 4.0.0
-      '@pnpm/types': 7.9.0
+      '@pnpm/types': 7.10.0
     dev: false
 
-  /@pnpm/fetch/4.2.4_@pnpm+logger@4.0.0:
-    resolution: {integrity: sha512-PnFPVxhAK0+mOgKsVMrzS1bFokeO3PB6/aaBBjQprtvBG6jYZ8d8JnHvwhRcCKM/LxqVsazMFgqYPEFyMjg0Pw==}
+  /@pnpm/fetch/4.2.5_@pnpm+logger@4.0.0:
+    resolution: {integrity: sha512-8zUWgrP+6mK/LJcLkNfjqKLSwOs4n/LR3BACZGSwcFH7yh28YJhKo142gFPOVTzS0pBUDvVVsDNQ7sxp2lOmDw==}
     engines: {node: '>=12.17'}
     peerDependencies:
       '@pnpm/logger': ^4.0.0
     dependencies:
-      '@pnpm/core-loggers': 6.1.3_@pnpm+logger@4.0.0
+      '@pnpm/core-loggers': 6.1.4_@pnpm+logger@4.0.0
       '@pnpm/fetching-types': 2.2.1
       '@pnpm/logger': 4.0.0
       '@pnpm/npm-registry-agent': 5.0.2
@@ -108,8 +108,8 @@ packages:
       - supports-color
     dev: false
 
-  /@pnpm/types/7.9.0:
-    resolution: {integrity: sha512-WJol7zZKMktP8bvoFEh/ANCrYsIDcfpGFgRZmAMeULuskFVND4NLXXIkBqNhtmv+ipt6mVUnsZTGHrVaXrlsNA==}
+  /@pnpm/types/7.10.0:
+    resolution: {integrity: sha512-7NKyfwepNccR6f9htiXAw0tt6rCajvtiX5HsTOi3odSFJ04iri43yjh70Ekw25hAynQwRR0rkJ7l6BBNFrJ/2g==}
     engines: {node: '>=12.17'}
     dev: false
 
@@ -286,8 +286,8 @@ packages:
     resolution: {integrity: sha512-qcUXuemtEu+E5wZSJHNxUXeCZhAfXKQ41D+duX+VYPde7xyEVZci+/oXKJL13tnRs9lR2pr4fod59GT6/X1/yQ==}
     dev: true
 
-  /@types/node-fetch/2.5.12:
-    resolution: {integrity: sha512-MKgC4dlq4kKNa/mYrwpKfzQMB5X3ee5U6fSprkKpToBqBmX4nFZL9cW5jl6sWn+xpRJ7ypWh2yyqqr8UUCstSw==}
+  /@types/node-fetch/2.6.1:
+    resolution: {integrity: sha512-oMqjURCaxoSIsHSr1E47QHzbmzNR5rK8McHuNb11BOM9cHcIK3Avy0s/b2JlXHoQGTYS3NsvWzV1M0iK7l0wbA==}
     dependencies:
       '@types/node': 14.18.10
       form-data: 3.0.1
@@ -310,8 +310,8 @@ packages:
       '@types/yargs-parser': 20.2.1
     dev: true
 
-  /@vercel/ncc/0.27.0:
-    resolution: {integrity: sha512-DllIJQapnU2YwewIhh/4dYesmMQw3h2cFtabECc/zSJHqUbNa0eJuEkRa6DXbZvh1YPWBtYQoPV17NlDpBw1Vw==}
+  /@vercel/ncc/0.33.3:
+    resolution: {integrity: sha512-JGZ11QV+/ZcfudW2Cz2JVp54/pJNXbsuWRgSh2ZmmZdQBKXqBtIGrwI1Wyx8nlbzAiEFe7FHi4K1zX4//jxTnQ==}
     hasBin: true
     dev: true
 
@@ -386,11 +386,6 @@ packages:
     resolution: {integrity: sha1-x57Zf380y48robyXkLzDZkdLS3k=}
     dev: false
 
-  /at-least-node/1.0.0:
-    resolution: {integrity: sha512-+q/t7Ekv1EDY2l6Gda6LLiX14rU9TV20Wa3ofeQmwPFZbOMo9DXrLbOjFaaclkXKWidIaopwAObQDqwWtGUjqg==}
-    engines: {node: '>= 4.0.0'}
-    dev: false
-
   /balanced-match/1.0.2:
     resolution: {integrity: sha512-3oSeUO0TMV67hN1AmbXsK4yaqU7tjiHlbxRDZOpH0KW9+CeX4bRAaX0Anxt0tx2MrpRpWwQaPwIlISEJhYU5Pw==}
     dev: true
@@ -580,6 +575,15 @@ packages:
       mime-types: 2.1.34
     dev: false
 
+  /fs-extra/10.0.0:
+    resolution: {integrity: sha512-C5owb14u9eJwizKGdchcDUQeFtlSHHthBk8pbX9Vc1PFZrLombudjDnNns88aYslCyF6IY5SUw3Roz6xShcEIQ==}
+    engines: {node: '>=12'}
+    dependencies:
+      graceful-fs: 4.2.9
+      jsonfile: 6.1.0
+      universalify: 2.0.0
+    dev: false
+
   /fs-extra/8.1.0:
     resolution: {integrity: sha512-yhlQgA6mnOJUKOsRUFsgJdQCvkKhcz8tlZG5HBQfReYZy46OwLcY+Zia0mtdHsOo9y/hP+CxMN0TU9QxoOtG4g==}
     engines: {node: '>=6 <7 || >=8'}
@@ -589,16 +593,6 @@ packages:
       universalify: 0.1.2
     dev: true
 
-  /fs-extra/9.1.0:
-    resolution: {integrity: sha512-hcg3ZmepS30/7BSFqRvoo3DOMQu7IjqxO5nCDt+zM9XWjb33Wg7ziNT+Qvqbuc3+gWpzO02JubVyk2G4Zvo1OQ==}
-    engines: {node: '>=10'}
-    dependencies:
-      at-least-node: 1.0.0
-      graceful-fs: 4.2.9
-      jsonfile: 6.1.0
-      universalify: 2.0.0
-    dev: false
-
   /fs.realpath/1.0.0:
     resolution: {integrity: sha1-FQStJSMVjKpA20onh8sBQRmU6k8=}
     dev: true
diff --git a/src/inputs/index.ts b/src/inputs/index.ts
index 142fcae..db07108 100644
--- a/src/inputs/index.ts
+++ b/src/inputs/index.ts
@@ -3,7 +3,7 @@ import expandTilde from 'expand-tilde'
 import { RunInstall, parseRunInstall } from './run-install'
 
 export interface Inputs {
-  readonly version: string
+  readonly version?: string
   readonly dest: string
   readonly runInstall: RunInstall[]
 }
@@ -15,7 +15,7 @@ const options: InputOptions = {
 const parseInputPath = (name: string) => expandTilde(getInput(name, options))
 
 export const getInputs = (): Inputs => ({
-  version: getInput('version', options),
+  version: getInput('version'),
   dest: parseInputPath('dest'),
   runInstall: parseRunInstall('run_install'),
 })
diff --git a/src/install-pnpm/run.ts b/src/install-pnpm/run.ts
index 597ceec..0798190 100644
--- a/src/install-pnpm/run.ts
+++ b/src/install-pnpm/run.ts
@@ -2,14 +2,14 @@ import { addPath, exportVariable } from '@actions/core'
 import { spawn } from 'child_process'
 import { execPath } from 'process'
 import path from 'path'
-import { remove, ensureFile, writeFile } from 'fs-extra'
+import { remove, ensureFile, writeFile, readFile } from 'fs-extra'
 import fetch from '@pnpm/fetch'
 import { Inputs } from '../inputs'
 
 export async function runSelfInstaller(inputs: Inputs): Promise<number> {
   const { version, dest } = inputs
-  const target = version ? `pnpm@${version}` : 'pnpm'
   const pkgJson = path.join(dest, 'package.json')
+  const target = await readTarget(pkgJson, version)
 
   await remove(dest)
   await ensureFile(pkgJson)
@@ -36,4 +36,21 @@ export async function runSelfInstaller(inputs: Inputs): Promise<number> {
   return exitCode
 }
 
+async function readTarget(packageJsonPath: string, version?: string | undefined) {
+  if (version) return `pnpm@${version}`
+
+  const { packageManager } = JSON.parse(await readFile(packageJsonPath, 'utf8'))
+  if (typeof packageManager !== 'string') {
+    throw new Error(`No pnpm version is specified.
+Please specify it by one of the following ways:
+  - in the GitHub Action config with the key "version"
+  - in the package.json with the key "packageManager" (See https://nodejs.org/api/corepack.html)`)
+  }
+
+  if (!packageManager.startsWith('pnpm@')) {
+    throw new Error('Invalid packageManager field in package.json')
+  }
+  return packageManager
+}
+
 export default runSelfInstaller