diff --git a/.changeset/bun-lockfile-not-detected-in-detectpm.md b/.changeset/bun-lockfile-not-detected-in-detectpm.md
new file mode 100644
index 0000000..544c338
--- /dev/null
+++ b/.changeset/bun-lockfile-not-detected-in-detectpm.md
@@ -0,0 +1,5 @@
+---
+"@generata/core": patch
+---
+
+fix(cli): detect bun lockfile in detectPm
diff --git a/packages/core/src/cli/pm.test.ts b/packages/core/src/cli/pm.test.ts
new file mode 100644
index 0000000..5e97894
--- /dev/null
+++ b/packages/core/src/cli/pm.test.ts
@@ -0,0 +1,27 @@
+import { strictEqual } from "node:assert/strict";
+import { describe, it, before, after } from "node:test";
+import { mkdtempSync, writeFileSync, rmSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { detectPm } from "./pm.js";
+
+let dir: string;
+const originalUa = process.env.npm_config_user_agent;
+
+describe("detectPm", () => {
+  before(() => {
+    dir = mkdtempSync(join(tmpdir(), "pm-detect-"));
+  });
+  after(() => {
+    rmSync(dir, { recursive: true, force: true });
+    if (originalUa === undefined) delete process.env.npm_config_user_agent;
+    else process.env.npm_config_user_agent = originalUa;
+  });
+
+  it("returns 'bun' when bun.lockb is present, even if user-agent is pnpm", () => {
+    const dest = mkdtempSync(join(dir, "bun-"));
+    writeFileSync(join(dest, "bun.lockb"), "");
+    process.env.npm_config_user_agent = "pnpm/9.0.0 npm/? node/v20.0.0 darwin arm64";
+    strictEqual(detectPm(dest), "bun");
+  });
+});
diff --git a/packages/core/src/cli/pm.ts b/packages/core/src/cli/pm.ts
index 0de5c67..054fe23 100644
--- a/packages/core/src/cli/pm.ts
+++ b/packages/core/src/cli/pm.ts
@@ -5,6 +5,7 @@ export function detectPm(dest: string): string {
   if (existsSync(join(dest, "pnpm-lock.yaml"))) return "pnpm";
   if (existsSync(join(dest, "yarn.lock"))) return "yarn";
   if (existsSync(join(dest, "package-lock.json"))) return "npm";
+  if (existsSync(join(dest, "bun.lockb"))) return "bun";
   // Fresh init: match whatever PM invoked us (npx -> npm, pnpm dlx -> pnpm, etc.)
   const ua = process.env.npm_config_user_agent ?? "";
   if (ua.startsWith("pnpm")) return "pnpm";