diff --git a/scripts/__tests__/public-install-registry.test.mjs b/scripts/__tests__/public-install-registry.test.mjs
index 1edd1ff7573..a175a8274fe 100644
--- a/scripts/__tests__/public-install-registry.test.mjs
+++ b/scripts/__tests__/public-install-registry.test.mjs
@@ -124,7 +124,9 @@ test('the registry exposes only known tarballs, redirects other packages to npm
     assert.equal(await (await fetch(metadata.versions['1.0.0'].dist.tarball)).text(), 'packed bytes');
     const external = await fetch(`${registry.url}/@other%2fpkg`, { redirect: 'manual' });
     assert.equal(external.status, 302);
-    assert.equal(external.headers.get('location'), 'https://registry.npmjs.org/%40other%2Fpkg');
+    assert.equal(external.headers.get('location'), 'https://registry.npmjs.org/@other%2fpkg');
+    const unscoped = await fetch(`${registry.url}/other-pkg`, { redirect: 'manual' });
+    assert.equal(unscoped.headers.get('location'), 'https://registry.npmjs.org/other-pkg');
     assert.equal((await fetch(`${registry.url}/-/900.tgz`)).status, 404);
     assert.equal((await fetch(`${registry.url}/some%2foutside%2ffile`)).status, 404);
     assert.equal((await fetch(`${registry.url}/@ci%2fpkg`, { method: 'POST' })).status, 405);
diff --git a/scripts/public-install-registry.mjs b/scripts/public-install-registry.mjs
index b0b6d80c994..06a23b64683 100644
--- a/scripts/public-install-registry.mjs
+++ b/scripts/public-install-registry.mjs
@@ -54,7 +54,7 @@ export async function startPackedRegistry(directory) {
     if (!packageName.test(path)) { response.writeHead(404).end(); return; }
     const entry = packages.get(path);
     if (!entry) {
-      response.writeHead(302, { location: `https://registry.npmjs.org/${encodeURIComponent(path)}` }).end();
+      response.writeHead(302, { location: `https://registry.npmjs.org/${path.replace('/', '%2f')}` }).end();
       return;
     }
     const { manifest, integrity } = entry;