diff --git a/examples/reactrouter/server.ts b/examples/reactrouter/server.ts
index 80ee0542c..616e15d33 100644
--- a/examples/reactrouter/server.ts
+++ b/examples/reactrouter/server.ts
@@ -41,7 +41,7 @@ async function startServer() {
 
     // TUS upload endpoints (before React Router)
     app.all('/api/upload/tus', (req, res) => tusServer.handle(req, res))
-    app.all('/api/upload/tus/*', (req, res) => tusServer.handle(req, res))
+    app.all('/api/upload/tus/{*splat}', (req, res) => tusServer.handle(req, res))
 
     // Handle Chrome DevTools requests silently
     app.get('/.well-known/appspecific/com.chrome.devtools.json', (req, res) => {
@@ -49,7 +49,7 @@ async function startServer() {
     })
 
     // React Router handles all other routes
-    app.all('*', reactRouterHandler)
+    app.all('/{*splat}', reactRouterHandler)
 
     const port = process.env.PORT || 3000
     const server = app.listen(port, () => {
diff --git a/packages/@uppy/companion/src/companion.ts b/packages/@uppy/companion/src/companion.ts
index fb98e6782..290b66561 100644
--- a/packages/@uppy/companion/src/companion.ts
+++ b/packages/@uppy/companion/src/companion.ts
@@ -125,6 +125,9 @@ export function app(optionsArg: CompanionInitOptions) {
 
   const app = express()
 
+  // Needed for e.g. s3 `/params` endpoint metadata, like `metadata[key]=value` to be parsed into a metadata object
+  app.set('query parser', 'extended')
+
   if (options.metrics) {
     app.use(middlewares.metrics({ path: options.server.path }))
   }
diff --git a/packages/@uppy/companion/test/companion.test.ts b/packages/@uppy/companion/test/companion.test.ts
index be3f458a6..4eef1110b 100644
--- a/packages/@uppy/companion/test/companion.test.ts
+++ b/packages/@uppy/companion/test/companion.test.ts
@@ -426,4 +426,26 @@ describe('S3 controller', () => {
         ),
       )
   })
+
+  test('getUploadParameters supports bracket metadata query format', async () => {
+    const server = await getServer({
+      COMPANION_AWS_KEY: 'test_key',
+      COMPANION_AWS_SECRET: 'test_secret',
+      COMPANION_AWS_BUCKET: 'test-bucket',
+      COMPANION_AWS_REGION: 'us-east-1',
+    })
+
+    return request(server)
+      .get('/s3/params')
+      .query({
+        filename: 'test.txt',
+        type: 'text/plain',
+        'metadata[name]': 'demo-file',
+      })
+      .expect(200)
+      .then((res) => {
+        const fields = res.body.fields as Record<string, string>
+        expect(fields['x-amz-meta-name']).toBe('demo-file')
+      })
+  })
 })