diff --git a/.github/workflows/test.yaml b/.github/workflows/test.yaml
index bd024e7..6299b63 100644
--- a/.github/workflows/test.yaml
+++ b/.github/workflows/test.yaml
@@ -194,6 +194,52 @@ jobs:
           pnpm add is-odd
         shell: bash
 
+  cache_store_path:
+    # Regression guard for #233. When package.json pins a pnpm major that
+    # differs from the bootstrap pnpm's major, the bootstrap reports its
+    # own STORE_VERSION from `pnpm store path` (the `store` command skips
+    # pnpm's auto-switch). The user's actual `pnpm install` runs under the
+    # pinned version and writes to a different STORE_VERSION, so the post
+    # step's saveCache then fails with "Path Validation Error". The fix is
+    # to self-update the bootstrap to the pinned version up front.
+    name: 'Cache store path matches install (#233): ${{ matrix.label }}'
+
+    runs-on: ubuntu-latest
+
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - label: 'packageManager pnpm@10.33.0'
+            manifest: '{"packageManager":"pnpm@10.33.0","dependencies":{"is-odd":"3.0.1"}}'
+          - label: 'devEngines exact pnpm@10.33.0'
+            manifest: '{"devEngines":{"packageManager":{"name":"pnpm","version":"10.33.0"}},"dependencies":{"is-odd":"3.0.1"}}'
+
+    steps:
+      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
+
+      - name: Set up package.json
+        run: echo '${{ matrix.manifest }}' > package.json
+        shell: bash
+
+      - id: pnpm
+        uses: ./
+        with:
+          cache: true
+          run_install: |
+            - args: [--no-frozen-lockfile]
+
+      - name: 'Test: store path computed by the action exists on disk'
+        run: |
+          set -e
+          actual="$(pnpm store path --silent)"
+          echo "pnpm store path: ${actual}"
+          if [ ! -d "${actual}" ]; then
+            echo "Expected store path to exist on disk; cache save would fail"
+            exit 1
+          fi
+        shell: bash
+
   run_install:
     name: 'run_install (${{ matrix.run_install.name }})'
 
diff --git a/dist/index.js b/dist/index.js
index 4c2ed42..ddb8afe 100644
Binary files a/dist/index.js and b/dist/index.js differ
diff --git a/src/install-pnpm/run.ts b/src/install-pnpm/run.ts
index ffcf3b8..0afe211 100644
--- a/src/install-pnpm/run.ts
+++ b/src/install-pnpm/run.ts
@@ -98,15 +98,21 @@ export async function runSelfInstaller(inputs: Inputs): Promise<SelfInstallerRes
     // the bootstrap symlinks in pnpmHome pointing at the old version. Use
     // PNPM_HOME/bin so consumers of the bin_dest output (e.g.
     // `${steps.pnpm.outputs.bin_dest}/pnpm`) invoke the requested version.
-    return { exitCode: 0, binDest: path.join(pnpmHome, 'bin') }
+    //
+    // When the requested version equals the bootstrap version, self-update
+    // is a no-op and PNPM_HOME/bin/pnpm is not created — fall back to
+    // pnpmHome, whose symlinks already point at the right version.
+    const updatedBin = path.join(pnpmHome, 'bin', process.platform === 'win32' ? 'pnpm.exe' : 'pnpm')
+    return { exitCode: 0, binDest: existsSync(updatedBin) ? path.join(pnpmHome, 'bin') : pnpmHome }
   }
 
-  // No explicit target version: rely on the bootstrap pnpm to switch to
-  // the version declared in packageManager/devEngines at runtime. Force
-  // `pmOnFail=download` so a project that pins
-  // `devEngines.packageManager.onFail = "error"` doesn't trip BAD_PM_VERSION
-  // before the switch can happen (issue #252). Scoped to this branch so users
-  // who pass an explicit `version:` input keep strict onFail behavior.
+  // No exact target version we can self-update to (devEngines pins a
+  // semver range, or nothing is pinned at all). Rely on the bootstrap
+  // pnpm to switch versions at runtime. Force `pmOnFail=download` so a
+  // project that pins `devEngines.packageManager.onFail = "error"` doesn't
+  // trip BAD_PM_VERSION before the switch can happen (issue #252). Scoped
+  // to this branch so users who pass an explicit `version:` input keep
+  // strict onFail behavior.
   exportVariable('pnpm_config_pm_on_fail', 'download')
   return { exitCode: 0, binDest: pnpmHome }
 }
@@ -135,12 +141,15 @@ function readTargetVersion(opts: {
     }
   }
 
+  // packageManager is always exact `pnpm@<version>[+<integrity>]` per spec.
+  // Strip the integrity hash for self-update.
+  const packageManagerVersion =
+    typeof packageManager === 'string' && packageManager.startsWith('pnpm@')
+      ? packageManager.slice('pnpm@'.length).split('+')[0]
+      : undefined
+
   if (version) {
-    if (
-      typeof packageManager === 'string' &&
-      packageManager.startsWith('pnpm@') &&
-      packageManager.replace('pnpm@', '') !== version
-    ) {
+    if (packageManagerVersion && packageManagerVersion !== version) {
       throw new Error(`Multiple versions of pnpm specified:
   - version ${version} in the GitHub Action config with the key "version"
   - version ${packageManager} in the package.json with the key "packageManager"
@@ -150,13 +159,27 @@ Remove one of these versions to avoid version mismatch errors like ERR_PNPM_BAD_
     return version
   }
 
-  // pnpm will automatically download and switch to the right version
-  if (typeof packageManager === 'string' && packageManager.startsWith('pnpm@')) {
+  // Self-update the bootstrap pnpm to the version pinned in package.json so
+  // PATH-resolved `pnpm` (and the bin_dest output) reflect the target
+  // version. Without this, `pnpm store path` runs as the bootstrap and
+  // reports a different STORE_VERSION than the one the user's actual
+  // install writes to — breaking cache: true and actions/setup-node's
+  // `cache: pnpm` on cold caches (issue #233).
+  //
+  // devEngines.packageManager takes priority over packageManager, matching
+  // pnpm's getWantedPackageManager logic. devEngines.packageManager.version
+  // can be a semver range; `pnpm self-update` needs a specific version, so
+  // for ranges we fall through to the bootstrap auto-switch path.
+  if (devEngines?.packageManager?.name === 'pnpm') {
+    const v = devEngines.packageManager.version
+    if (v != null && isExactSemver(v)) {
+      return v
+    }
     return undefined
   }
 
-  if (devEngines?.packageManager?.name === 'pnpm' && devEngines.packageManager.version) {
-    return undefined
+  if (packageManagerVersion) {
+    return packageManagerVersion
   }
 
   if (!GITHUB_WORKSPACE) {
@@ -173,6 +196,10 @@ Please specify it by one of the following ways:
   - in the package.json with the key "devEngines.packageManager"`)
 }
 
+function isExactSemver(v: string): boolean {
+  return /^\d+\.\d+\.\d+(?:-[0-9A-Za-z-]+(?:\.[0-9A-Za-z-]+)*)?(?:\+[0-9A-Za-z-]+(?:\.[0-9A-Za-z-]+)*)?$/.test(v)
+}
+
 function getSystemNodeVersion(): Promise<{ major: number; minor: number }> {
   return new Promise((resolve) => {
     const cp = spawn('node', ['--version'], { stdio: ['pipe', 'pipe', 'pipe'], shell: process.platform === 'win32' })