diff --git a/.gitattributes b/.gitattributes
new file mode 100644
index 00000000..d3c8713c
--- /dev/null
+++ b/.gitattributes
@@ -0,0 +1,18 @@
+# Normalize line endings to LF for every tracked text file, regardless of a
+# contributor's local core.autocrlf setting. Several guards and tests compare
+# file content or hash it (e.g. guards/markdown-links.mjs, patches applied via
+# pnpm, CI-workflow regex assertions in scripts/release*.test.mjs) and break or
+# silently diverge when a checkout introduces CRLF bytes that were not in the
+# reviewed source.
+* text=auto eol=lf
+
+# Explicitly binary — never subject to line-ending normalization or diffing.
+*.png binary
+*.jpg binary
+*.jpeg binary
+*.gif binary
+*.ico binary
+*.woff binary
+*.woff2 binary
+*.ttf binary
+*.otf binary
diff --git a/guards/markdown-links.mjs b/guards/markdown-links.mjs
index d55f7fdb..fe477ec5 100644
--- a/guards/markdown-links.mjs
+++ b/guards/markdown-links.mjs
@@ -138,9 +138,11 @@ export default {
   name: "markdown-links",
   description: "tracked Markdown files do not link to missing local targets",
   run() {
-    const root = execFileSync("git", ["rev-parse", "--show-toplevel"], {
-      encoding: "utf8",
-    }).trim();
+    const root = resolve(
+      execFileSync("git", ["rev-parse", "--show-toplevel"], {
+        encoding: "utf8",
+      }).trim(),
+    );
     const violations = [];
 
     for (const file of trackedMarkdownFiles(root)) {
diff --git a/scripts/dependencies-security.test.mjs b/scripts/dependencies-security.test.mjs
index 76f850ab..bea95055 100644
--- a/scripts/dependencies-security.test.mjs
+++ b/scripts/dependencies-security.test.mjs
@@ -1,6 +1,6 @@
 import assert from "node:assert/strict";
 import { spawnSync } from "node:child_process";
-import { readFile } from "node:fs/promises";
+import { readdir, readFile } from "node:fs/promises";
 import { dirname, join, resolve } from "node:path";
 import test from "node:test";
 import { fileURLToPath, pathToFileURL } from "node:url";
@@ -11,16 +11,16 @@ async function patchedImageSizeModule() {
   const lockfile = await readFile(join(root, "pnpm-lock.yaml"), "utf8");
   const match = lockfile.match(/^  image-size@2\.0\.2: ([a-f0-9]+)$/m);
   assert.ok(match, "image-size 2.0.2 must remain pinned to the reviewed local patch");
-  return join(
-    root,
-    "node_modules",
-    ".pnpm",
-    `image-size@2.0.2_patch_hash=${match[1]}`,
-    "node_modules",
-    "image-size",
-    "dist",
-    "index.mjs",
+
+  const storeDir = join(root, "node_modules", ".pnpm");
+  const entries = await readdir(storeDir);
+  const patchedEntry = entries.find((entry) => /^image-size@2\.0\.2_patch_hash[=_][a-f0-9]+$/.test(entry));
+  assert.ok(
+    patchedEntry,
+    "expected a patched image-size@2.0.2 entry under node_modules/.pnpm — run pnpm install",
   );
+
+  return join(storeDir, patchedEntry, "node_modules", "image-size", "dist", "index.mjs");
 }
 
 function writeBox(buffer, offset, size, name) {
diff --git a/scripts/release.integration.test.mjs b/scripts/release.integration.test.mjs
index cb75d7e6..796e7969 100644
--- a/scripts/release.integration.test.mjs
+++ b/scripts/release.integration.test.mjs
@@ -32,7 +32,7 @@ async function fixture(t) {
     join(packageDir, "lifecycle.mjs"),
     "import { writeFileSync } from 'node:fs';\nwriteFileSync(process.env.RELEASE_LIFECYCLE_MARKER, 'ran');\n",
   );
-  execFileSync("tar", ["-czf", tarball, "-C", root, "package"]);
+  execFileSync("tar", ["--force-local", "-czf", tarball, "-C", root, "package"]);
 
   t.after(async () => {
     await rm(root, { recursive: true, force: true });
diff --git a/scripts/release.mjs b/scripts/release.mjs
index 53c06501..b4bca626 100644
--- a/scripts/release.mjs
+++ b/scripts/release.mjs
@@ -129,7 +129,7 @@ export function inspectTarball(tarball, { exec = execFileSync } = {}) {
   let manifest;
   try {
     manifest = JSON.parse(
-      exec("tar", ["-xOf", absolute, "package/package.json"], { encoding: "utf8" }),
+      exec("tar", ["--force-local", "-xOf", absolute, "package/package.json"], { encoding: "utf8" }),
     );
   } catch (error) {
     throw new Error(`cannot read package/package.json from ${absolute}: ${error.message}`);