diff --git a/.github/workflows/pr.yml b/.github/workflows/pr.yml
index 742cbd6e56b..fcc192412f2 100644
--- a/.github/workflows/pr.yml
+++ b/.github/workflows/pr.yml
@@ -638,6 +638,7 @@ jobs:
           src/main/windows/windows-host-job.win32.test.ts
           src/main/cli/wsl-cli-powershell-boundary.test.ts
           src/main/orca-profiles/profile-index-store.test.ts
+          config/scripts/generate-bundled-skill-guides.test.mjs
           src/main/runtime/repo-worktree-admin-fingerprint.test.ts
           src/main/runtime/worktree-scan-admin-fingerprint-gate.test.ts
           src/shared/secure-file-fsync-flags.test.ts
diff --git a/config/scripts/generate-bundled-skill-guides.mjs b/config/scripts/generate-bundled-skill-guides.mjs
index f78ce1402b0..bc44f5e72d6 100644
--- a/config/scripts/generate-bundled-skill-guides.mjs
+++ b/config/scripts/generate-bundled-skill-guides.mjs
@@ -169,6 +169,12 @@ async function assertStubSourcesMatchTopics(repoRoot) {
   }
 }
 
+// Why: path.relative yields `\` on Windows, but these paths are asserted in tests and pasted into commands.
+// split(sep) rather than replaceAll('\\', '/') so a POSIX filename containing a backslash survives intact.
+function toPosixRelativePath(repoRoot, filePath, pathModule = path) {
+  return pathModule.relative(repoRoot, filePath).split(pathModule.sep).join('/')
+}
+
 async function buildArtifacts(repoRoot = REPO_ROOT) {
   const guideRoot = path.join(repoRoot, 'skill-guides')
   const sourceFiles = (await readdir(guideRoot, { withFileTypes: true }))
@@ -193,7 +199,7 @@ async function buildArtifacts(repoRoot = REPO_ROOT) {
     // Why: Git may render text with native EOLs despite repository policy; the
     // embedded guide and generated projection must have one platform-neutral identity.
     const markdown = normalizeMarkdown(await readFile(sourcePath, 'utf8'))
-    const frontmatter = parseFrontmatter(markdown, path.relative(repoRoot, sourcePath))
+    const frontmatter = parseFrontmatter(markdown, toPosixRelativePath(repoRoot, sourcePath))
     if (frontmatter.name !== name) {
       throw new Error(`Guide source ${name}.md declares mismatched name ${frontmatter.name}`)
     }
@@ -243,7 +249,7 @@ async function verifyArtifacts(artifacts, repoRoot = REPO_ROOT) {
   if (stale.length > 0) {
     throw new Error(
       `Generated bundled skill guides are stale:\n${stale
-        .map((filePath) => path.relative(repoRoot, filePath).split(path.sep).join('/'))
+        .map((filePath) => toPosixRelativePath(repoRoot, filePath))
         .join('\n')}\nRun node config/scripts/generate-bundled-skill-guides.mjs --write.`
     )
   }
@@ -272,6 +278,7 @@ export {
   normalizeMarkdown,
   parseFrontmatter,
   serializeEmbeddedModule,
+  toPosixRelativePath,
   verifyArtifacts,
   writeArtifacts
 }
diff --git a/config/scripts/generate-bundled-skill-guides.test.mjs b/config/scripts/generate-bundled-skill-guides.test.mjs
index e756157595b..e8e456f9934 100644
--- a/config/scripts/generate-bundled-skill-guides.test.mjs
+++ b/config/scripts/generate-bundled-skill-guides.test.mjs
@@ -14,6 +14,7 @@ import {
   frontmatterBlock,
   normalizeMarkdown,
   parseFrontmatter,
+  toPosixRelativePath,
   verifyArtifacts,
   writeArtifacts
 } from './generate-bundled-skill-guides.mjs'
@@ -232,6 +233,20 @@ describe('bundled skill guide generator', () => {
     await expect(verifyArtifacts(artifacts, root)).rejects.toThrow('skills/computer-use/SKILL.md')
   })
 
+  // Why: the stale-artifact assertions above only exercise the Windows separator on Windows,
+  // and this file is not in pr.yml's Windows test allowlist — inject path.win32 so CI covers it.
+  it('formats contributor-facing paths with forward slashes on every platform', () => {
+    expect(
+      toPosixRelativePath('C:\\repo', 'C:\\repo\\src\\cli\\bundled-skill-guides.ts', path.win32)
+    ).toBe('src/cli/bundled-skill-guides.ts')
+    expect(
+      toPosixRelativePath('C:\\repo', 'C:\\repo\\skills\\computer-use\\SKILL.md', path.win32)
+    ).toBe('skills/computer-use/SKILL.md')
+    expect(toPosixRelativePath('/repo', '/repo/skills/computer-use/SKILL.md', path.posix)).toBe(
+      'skills/computer-use/SKILL.md'
+    )
+  })
+
   it('rejects mismatched source names and ambiguous aliases', async () => {
     const root = await createFixture()
     await writeFile(