diff --git a/deslop-shared-libs/SKILL.md b/deslop-shared-libs/SKILL.md
index dd0b7a45a..9a5fbead3 100644
--- a/deslop-shared-libs/SKILL.md
+++ b/deslop-shared-libs/SKILL.md
@@ -72,7 +72,7 @@ changed after writing one.
    protections and refuses reads that could run filters, drivers, hooks or
    transports, naming the allowed forms. Never bypass a refusal with raw `git`.
    `diff` takes exactly two explicit committed object IDs, then `--` and paths.
-   First probe with `~/.claude/skills/gstack/bin/gstack-safe-git rev-parse --is-inside-work-tree`; a Git
+   First probe the audited repository with `~/.claude/skills/gstack/bin/gstack-safe-git -C <repo> rev-parse --is-inside-work-tree` (use `-C <repo>` on every call when your shell is elsewhere); a Git
    version check alone is insufficient. If the probe fails (for example
    `unknown option: --no-lazy-fetch`), use pinned-commit GET API source
    and history reads or disclose unavailable local-history coverage. Never retry
diff --git a/deslop-shared-libs/SKILL.md.tmpl b/deslop-shared-libs/SKILL.md.tmpl
index d85a53e9d..29cf64c5d 100644
--- a/deslop-shared-libs/SKILL.md.tmpl
+++ b/deslop-shared-libs/SKILL.md.tmpl
@@ -66,7 +66,7 @@ changed after writing one.
    protections and refuses reads that could run filters, drivers, hooks or
    transports, naming the allowed forms. Never bypass a refusal with raw `git`.
    `diff` takes exactly two explicit committed object IDs, then `--` and paths.
-   First probe with `{{SAFE_GIT}} rev-parse --is-inside-work-tree`; a Git
+   First probe the audited repository with `{{SAFE_GIT}} -C <repo> rev-parse --is-inside-work-tree` (use `-C <repo>` on every call when your shell is elsewhere); a Git
    version check alone is insufficient. If the probe fails (for example
    `unknown option: --no-lazy-fetch`), use pinned-commit GET API source
    and history reads or disclose unavailable local-history coverage. Never retry
diff --git a/test/shared-libs-fixture.test.ts b/test/shared-libs-fixture.test.ts
index e847be614..15c798a72 100644
--- a/test/shared-libs-fixture.test.ts
+++ b/test/shared-libs-fixture.test.ts
@@ -36,7 +36,7 @@ describe('shared-code Git guard', () => {
     installSourceShims(f);
     const instructions = fs.readFileSync(standaloneInstructions(f), 'utf8');
     const helper = path.join(SHARED_LIBS_ROOT, 'bin/gstack-safe-git');
-    expect(instructions).toContain(`\`${helper} rev-parse --is-inside-work-tree\``);
+    expect(instructions).toContain(`\`${helper} -C <repo> rev-parse --is-inside-work-tree\``);
     expect(instructions).not.toContain('~/.claude/skills/gstack');
     const run = (command: string, args: string[]) => spawnSync(command, args, {
       cwd: f.repo, encoding: 'utf8', timeout: 10_000, env: { ...process.env, ...f.env } });
diff --git a/test/shared-libs-rendering.test.ts b/test/shared-libs-rendering.test.ts
index c750ecc75..b2c80d95f 100644
--- a/test/shared-libs-rendering.test.ts
+++ b/test/shared-libs-rendering.test.ts
@@ -56,7 +56,7 @@ describe('shared-code skill distribution', () => {
       expect(standalone).toContain('Keep API responses and intermediate data on stdout or in memory');
       // Git safety is the installed helper from the trusted global runtime, not a retyped prefix.
       const safeGit = `~/${host.globalRoot}/bin/gstack-safe-git`;
-      expect(standalone).toContain(`${safeGit} rev-parse --is-inside-work-tree`);
+      expect(standalone).toContain(`${safeGit} -C <repo> rev-parse --is-inside-work-tree`);
       expect(standalone).toContain(`${safeGit} ls-files --cached --others --exclude-standard -z`);
       expect(standalone).toContain('never bare `git`');
       expect(standalone).not.toContain('git --no-pager');