diff --git a/scripts/package-artifacts.mjs b/scripts/package-artifacts.mjs
index 5934b9faf..5d615dd32 100644
--- a/scripts/package-artifacts.mjs
+++ b/scripts/package-artifacts.mjs
@@ -31,10 +31,10 @@ function packPackages(packages, tarballDirectory) {
 			stdio: ["inherit", "pipe", "inherit"],
 		});
 		const parsed = JSON.parse(output);
-		if (!Array.isArray(parsed) || parsed.length !== 1 || !parsed[0]?.filename) {
+		const packed = Array.isArray(parsed) ? (parsed.length === 1 ? parsed[0] : undefined) : parsed?.[pkg.name];
+		if (packed?.name !== pkg.name || typeof packed.filename !== "string") {
 			throw new Error(`npm pack returned an unexpected result for ${pkg.name}`);
 		}
-		const packed = parsed[0];
 
 		const originalPath = join(tarballDirectory, packed.filename);
 		const contents = readFileSync(originalPath);
diff --git a/scripts/package-artifacts.test.mjs b/scripts/package-artifacts.test.mjs
index b5ec291f5..52aa7e1ee 100644
--- a/scripts/package-artifacts.test.mjs
+++ b/scripts/package-artifacts.test.mjs
@@ -15,6 +15,7 @@ function writePackage(directory, manifest, files) {
 	}
 }
 
+// #10633: Covers npm 12's package-keyed `npm pack --json` output only when npm 12 is on PATH.
 test("produces a verified, content-addressed artifact set", (t) => {
 	const temporaryRoot = mkdtempSync(join(tmpdir(), "pi-package-artifacts-test-"));
 	t.after(() => rmSync(temporaryRoot, { recursive: true, force: true }));