diff --git a/src/utils/serve-functions.js b/src/utils/serve-functions.js
index e31963ea9d0..b2c2c8d26b6 100644
--- a/src/utils/serve-functions.js
+++ b/src/utils/serve-functions.js
@@ -293,6 +293,7 @@ function createFormSubmissionHandler(siteInfo) {
 
 async function serveFunctions(dir, siteInfo = {}) {
   const app = express()
+  app.set('query parser', 'simple')
 
   app.use(
     bodyParser.text({
diff --git a/tests/dev.test.js b/tests/dev.test.js
index 054ef31992d..b197c0968a2 100644
--- a/tests/dev.test.js
+++ b/tests/dev.test.js
@@ -153,6 +153,12 @@ test('functions: not found', async t => {
   t.is(response.status, 404)
 })
 
+test('functions: query parameters parsing', async t => {
+  const response = await fetch(`http://${host}/api/echo?category[SOMETHING][]=something`).then(r => r.json())
+
+  t.deepEqual(response.queryStringParameters, { 'category[SOMETHING][]': 'something' })
+})
+
 test('Netlify Forms support', async t => {
   const form = new FormData()
   form.append('some', 'thing')