diff --git a/scripts/install-hooks.sh b/scripts/install-hooks.sh
index dd2a768..4aad880 100755
--- a/scripts/install-hooks.sh
+++ b/scripts/install-hooks.sh
@@ -5,10 +5,13 @@
 # (and so their hooks) run outside the sandbox. Re-run after changing anything in .githooks/.
 set -e
 cd "$(dirname "$0")/.."
-if ! hooks=$(git rev-parse --git-path hooks 2>/dev/null); then
+# Use the repo's own hooks directory, not `git rev-parse --git-path hooks`: that follows a
+# (possibly global) core.hooksPath and would install these hooks for every repo.
+if ! common=$(git rev-parse --git-common-dir 2>/dev/null); then
   echo "install-hooks: not a git checkout; skipping." >&2
   exit 0
 fi
+hooks="$common/hooks"
 mkdir -p "$hooks"
 for hook in .githooks/*; do
   cp "$hook" "$hooks/"
diff --git a/test/hooks.test.js b/test/hooks.test.js
index f9feea9..e49d8b3 100644
--- a/test/hooks.test.js
+++ b/test/hooks.test.js
@@ -1,7 +1,7 @@
 import { test, after } from "node:test";
 import assert from "node:assert/strict";
 import { spawnSync } from "node:child_process";
-import { mkdtempSync, rmSync, cpSync, statSync } from "node:fs";
+import { mkdtempSync, rmSync, cpSync, statSync, writeFileSync, existsSync } from "node:fs";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
 import { fileURLToPath } from "node:url";
@@ -74,6 +74,20 @@ test("install-hooks copies every hook into .git/hooks as an executable", () => {
   }
 });
 
+test("install-hooks ignores a global core.hooksPath", () => {
+  const repo = repoOn("fix/x");
+  const elsewhere = mkdtempSync(join(tmpdir(), "todo-hooks-"));
+  dirs.push(elsewhere);
+  const globalConfig = join(elsewhere, "gitconfig");
+  writeFileSync(globalConfig, `[core]\n\thooksPath = ${elsewhere}\n`);
+  cpSync(join(ROOT, "scripts"), join(repo, "scripts"), { recursive: true });
+  cpSync(HOOKS, join(repo, ".githooks"), { recursive: true });
+  const res = run("sh", [join(repo, "scripts", "install-hooks.sh")], { env: { ...env, GIT_CONFIG_GLOBAL: globalConfig } });
+  assert.equal(res.status, 0, res.stderr);
+  assert.ok(existsSync(join(repo, ".git", "hooks", "pre-push")));
+  assert.equal(existsSync(join(elsewhere, "pre-push")), false);
+});
+
 test("install-hooks skips cleanly outside a git checkout", () => {
   const dir = mkdtempSync(join(tmpdir(), "todo-hooks-"));
   dirs.push(dir);