diff --git a/README.md b/README.md
index ac14256..6d8bb23 100644
--- a/README.md
+++ b/README.md
@@ -44,7 +44,7 @@ If `run_install` is a YAML string representation of either an object or an array
 
 ### `package_json_file`
 
-**Optional** (_type:_ `string`, _default:_ `package.json`) File path to the `package.json`/[`package.yaml`](https://github.com/pnpm/pnpm/pull/1799) to read "packageManager" configuration.
+**Optional** (_type:_ `string`, _default:_ `package.json`) File path to the `package.json`/[`package.yaml`/`package.json5`](https://github.com/pnpm/pnpm/pull/1799) to read "packageManager" configuration.
 
 ### `standalone`
 
diff --git a/dist/index.js b/dist/index.js
index 425614a..770d72c 100644
Binary files a/dist/index.js and b/dist/index.js differ
diff --git a/package.json b/package.json
index ddb80fb..bb190f4 100644
--- a/package.json
+++ b/package.json
@@ -11,6 +11,7 @@
     "@types/expand-tilde": "^2.0.2",
     "@types/node": "^20.11.5",
     "expand-tilde": "^2.0.2",
+    "json5": "^2.2.3",
     "yaml": "^2.3.4",
     "zod": "^3.22.4"
   },
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 423eda5..527cf8b 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -20,6 +20,9 @@ importers:
       expand-tilde:
         specifier: ^2.0.2
         version: 2.0.2
+      json5:
+        specifier: ^2.2.3
+        version: 2.2.3
       yaml:
         specifier: ^2.3.4
         version: 2.7.0
@@ -69,6 +72,11 @@ packages:
     resolution: {integrity: sha512-eSmmWE5bZTK2Nou4g0AI3zZ9rswp7GRKoKXS1BLUkvPviOqs4YTN1djQIqrXy9k5gEtdLPy86JjRwsNM9tnDcA==}
     engines: {node: '>=0.10.0'}
 
+  json5@2.2.3:
+    resolution: {integrity: sha512-XmOWe7eyHYH14cLdVPoyg+GOH3rYX++KpzrylJwSW98t3Nk+U8XOl8FWKOgwtzdb8lXGf6zYwDUzeHMWfxasyg==}
+    engines: {node: '>=6'}
+    hasBin: true
+
   parse-passwd@1.0.0:
     resolution: {integrity: sha512-1Y1A//QUXEZK7YKz+rD9WydcE1+EuPr6ZBgKecAB8tmoW6UFv0NREVJe1p+jRxtThkcbbKkfwIbWJe/IeE6m2Q==}
     engines: {node: '>=0.10.0'}
@@ -131,6 +139,8 @@ snapshots:
     dependencies:
       parse-passwd: 1.0.0
 
+  json5@2.2.3: {}
+
   parse-passwd@1.0.0: {}
 
   pnpm@8.15.9: {}
diff --git a/src/install-pnpm/run.ts b/src/install-pnpm/run.ts
index f5b3ae0..ed883d5 100644
--- a/src/install-pnpm/run.ts
+++ b/src/install-pnpm/run.ts
@@ -7,6 +7,7 @@ import { execPath } from 'process'
 import util from 'util'
 import { Inputs } from '../inputs'
 import YAML from 'yaml'
+import JSON5 from 'json5'
 
 export async function runSelfInstaller(inputs: Inputs): Promise<number> {
   const { version, dest, packageJsonFile, standalone } = inputs
@@ -64,6 +65,8 @@ async function readTarget(opts: {
       const content = readFileSync(path.join(GITHUB_WORKSPACE, packageJsonFile), 'utf8');
       ({ packageManager } = packageJsonFile.endsWith(".yaml")
         ? YAML.parse(content, { merge: true })
+        : packageJsonFile.endsWith(".json5")
+        ? JSON5.parse(content)
         : JSON.parse(content)
       )
     } catch (error: unknown) {