diff --git a/__tests__/io.test.ts b/__tests__/io.test.ts
index c05be13..0fcab0d 100644
--- a/__tests__/io.test.ts
+++ b/__tests__/io.test.ts
@@ -643,8 +643,11 @@ describe('rmRF', () => {
       })
     ).toBe('test file content')
     if (os.platform() === 'win32') {
-      expect(await fs.readlink(symlinkLevel2Directory)).toBe(
-        `${symlinkDirectory}\\`
+      // Node.js 24 changed behavior - fs.readlink no longer includes trailing backslash
+      // Accept both formats for compatibility
+      const linkPath = await fs.readlink(symlinkLevel2Directory)
+      expect(linkPath.replace(/\\+$/, '')).toBe(
+        symlinkDirectory.replace(/\\+$/, '')
       )
     } else {
       expect(await fs.readlink(symlinkLevel2Directory)).toBe(symlinkDirectory)
@@ -1201,9 +1204,8 @@ describe('which', () => {
       const originalPath = process.env['PATH']
       try {
         // modify PATH
-        process.env[
-          'PATH'
-        ] = `${process.env['PATH']}${path.delimiter}${testPath}`
+        process.env['PATH'] =
+          `${process.env['PATH']}${path.delimiter}${testPath}`
 
         // find each file
         for (const fileName of Object.keys(files)) {
@@ -1274,9 +1276,8 @@ describe('which', () => {
       await fs.writeFile(notExpectedFilePath, '')
       const originalPath = process.env['PATH']
       try {
-        process.env[
-          'PATH'
-        ] = `${process.env['PATH']}${path.delimiter}${testPath}`
+        process.env['PATH'] =
+          `${process.env['PATH']}${path.delimiter}${testPath}`
         expect(await io.which(fileName)).toBe(expectedFilePath)
       } finally {
         process.env['PATH'] = originalPath
@@ -1438,9 +1439,8 @@ describe('findInPath', () => {
     try {
       // update the PATH
       for (const testPath of testPaths) {
-        process.env[
-          'PATH'
-        ] = `${process.env['PATH']}${path.delimiter}${testPath}`
+        process.env['PATH'] =
+          `${process.env['PATH']}${path.delimiter}${testPath}`
       }
       // exact file names
       expect(await io.findInPath(fileName)).toEqual(filePaths)
diff --git a/package-lock.json b/package-lock.json
index e7152dc..ddd87ac 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "@actions/io",
-  "version": "1.1.3",
-  "lockfileVersion": 2,
+  "version": "2.0.0",
+  "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "@actions/io",
-      "version": "1.1.3",
+      "version": "2.0.0",
       "license": "MIT"
     }
   }
diff --git a/package.json b/package.json
index e8c8d8f..f0be120 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@actions/io",
-  "version": "1.1.3",
+  "version": "2.0.0",
   "description": "Actions io lib",
   "keywords": [
     "github",
diff --git a/src/io-util.ts b/src/io-util.ts
index fd3a3e1..d75e64a 100644
--- a/src/io-util.ts
+++ b/src/io-util.ts
@@ -8,7 +8,6 @@ export const {
   mkdir,
   open,
   readdir,
-  readlink,
   rename,
   rm,
   rmdir,
@@ -18,6 +17,30 @@ export const {
 } = fs.promises
 // export const {open} = 'fs'
 export const IS_WINDOWS = process.platform === 'win32'
+
+/**
+ * Custom implementation of readlink to ensure Windows junctions
+ * maintain trailing backslash for backward compatibility with Node.js < 24
+ *
+ * In Node.js 20, Windows junctions (directory symlinks) always returned paths
+ * with trailing backslashes. Node.js 24 removed this behavior, which breaks
+ * code that relied on this format for path operations.
+ *
+ * This implementation restores the Node 20 behavior by adding a trailing
+ * backslash to all junction results on Windows.
+ */
+export async function readlink(fsPath: string): Promise<string> {
+  const result = await fs.promises.readlink(fsPath)
+
+  // On Windows, restore Node 20 behavior: add trailing backslash to all results
+  // since junctions on Windows are always directory links
+  if (IS_WINDOWS && !result.endsWith('\\')) {
+    return `${result}\\`
+  }
+
+  return result
+}
+
 // See https://github.com/nodejs/node/blob/d0153aee367422d0858105abec186da4dff0a0c5/deps/uv/include/uv/win.h#L691
 export const UV_FS_O_EXLOCK = 0x10000000
 export const READONLY = fs.constants.O_RDONLY