diff --git a/scripts/ci-release-checksums.test.ts b/scripts/ci-release-checksums.test.ts
index 78268c4b0..bc06811b1 100644
--- a/scripts/ci-release-checksums.test.ts
+++ b/scripts/ci-release-checksums.test.ts
@@ -1,6 +1,16 @@
-import { describe, expect, it } from "bun:test";
+import { afterEach, describe, expect, it } from "bun:test";
+import { mkdtemp, readFile, rm, writeFile } from "node:fs/promises";
+import { tmpdir } from "node:os";
+import * as path from "node:path";
+import { $ } from "bun";
 import { formatChecksums } from "./ci-release-checksums";
 
+const tempDirs: string[] = [];
+
+afterEach(async () => {
+	await Promise.all(tempDirs.splice(0).map(dir => rm(dir, { recursive: true, force: true })));
+});
+
 describe("formatChecksums", () => {
 	it("sorts entries by basename and formats as `sha256sum -c`-compatible lines", () => {
 		const output = formatChecksums([
@@ -10,6 +20,25 @@ describe("formatChecksums", () => {
 		expect(output).toBe(`${"a".repeat(64)}  omp-darwin-arm64\n${"b".repeat(64)}  omp-linux-x64\n`);
 	});
 
+	it("hashes assets and writes a sorted checksum manifest", async () => {
+		const dir = await mkdtemp(path.join(tmpdir(), "omp-release-checksums-"));
+		tempDirs.push(dir);
+		const aPath = path.join(dir, "omp-a");
+		const zPath = path.join(dir, "omp-z");
+		const outPath = path.join(dir, "SHA256SUMS.txt");
+		await Promise.all([writeFile(aPath, "abc"), writeFile(zPath, "")]);
+
+		const result = await $`bun ${path.join(import.meta.dir, "ci-release-checksums.ts")} ${outPath} ${zPath} ${aPath}`
+			.quiet()
+			.nothrow();
+
+		expect(result.exitCode).toBe(0);
+		expect(await readFile(outPath, "utf8")).toBe(
+			"ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad  omp-a\n" +
+				"e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855  omp-z\n",
+		);
+	});
+
 	it("returns an empty string for no entries", () => {
 		expect(formatChecksums([])).toBe("");
 	});