diff --git a/package.json b/package.json
index 772e836..c8c13bd 100644
--- a/package.json
+++ b/package.json
@@ -24,6 +24,7 @@
   "scripts": {
     "build": "tsup",
     "dev": "tsx src/index.ts",
+    "pretest": "npm run build",
     "test": "node --experimental-vm-modules node_modules/.bin/jest",
     "test:coverage": "node --experimental-vm-modules node_modules/.bin/jest --coverage",
     "lint": "eslint src/",
diff --git a/tests/bin-entries.test.ts b/tests/bin-entries.test.ts
new file mode 100644
index 0000000..3288267
--- /dev/null
+++ b/tests/bin-entries.test.ts
@@ -0,0 +1,49 @@
+import { existsSync, readFileSync } from 'node:fs';
+import { join } from 'node:path';
+
+const repoRoot = process.cwd();
+const pkg = JSON.parse(readFileSync(join(repoRoot, 'package.json'), 'utf-8')) as {
+  name: string;
+  bin?: string | Record<string, string>;
+  files?: string[];
+};
+
+function normalizeBin(bin: typeof pkg.bin, name: string): Array<[string, string]> {
+  if (typeof bin === 'string') return [[name, bin]];
+  if (bin && typeof bin === 'object') return Object.entries(bin);
+  return [];
+}
+
+function pkgFilesCoversPath(files: string[], relPath: string): boolean {
+  const clean = relPath.replace(/^\.\//, '');
+  const top = clean.split('/')[0];
+  return files.some((f) => {
+    const c = f.replace(/\/$/, '').replace(/^\.\//, '');
+    return c === top;
+  });
+}
+
+describe('package.json bin entries', () => {
+  const entries = normalizeBin(pkg.bin, pkg.name);
+  const files: string[] = pkg.files ?? [];
+
+  it('declares at least one bin entry', () => {
+    expect(entries.length).toBeGreaterThan(0);
+  });
+
+  it.each(entries)('bin "%s" -> "%s" exists on disk', (_name, rel) => {
+    const abs = join(repoRoot, rel.replace(/^\.\//, ''));
+    expect(existsSync(abs)).toBe(true);
+  });
+
+  it.each(entries)('bin "%s" -> "%s" starts with a node shebang', (_name, rel) => {
+    const abs = join(repoRoot, rel.replace(/^\.\//, ''));
+    if (!existsSync(abs)) return;
+    const firstLine = readFileSync(abs, 'utf-8').split('\n', 1)[0] ?? '';
+    expect(firstLine).toMatch(/^#!.*\bnode\b/);
+  });
+
+  it.each(entries)('bin "%s" -> "%s" lives under a directory in pkg.files', (_name, rel) => {
+    expect(pkgFilesCoversPath(files, rel)).toBe(true);
+  });
+});