diff --git a/lib/request.js b/lib/request.js
index c5ae50b..5c33923 100644
--- a/lib/request.js
+++ b/lib/request.js
@@ -21,7 +21,7 @@ const send = (url, formData, onSuccess, onError) => {
   request.post({ url, formData }, (err, res, body) => {
     if (err || res.statusCode !== 200) {
       err = err || new Error(`${res.statusMessage} (${res.statusCode}) - ${body}`)
-      if (res.statusCode < 400 || res.statusCode >= 500) {
+      if (res && (res.statusCode < 400 || res.statusCode >= 500)) {
         err.isRetryable = true
       }
       onError(err)
diff --git a/test/integration.test.js b/test/integration.test.js
index 8d42f16..831ffc2 100644
--- a/test/integration.test.js
+++ b/test/integration.test.js
@@ -77,6 +77,21 @@ test('it doesn’t retry on a 40x failure', () => {
   })
 })
 
+test('it returns the correct error in a synchronous failure', () => {
+  return upload({
+    apiKey: 'API_KEY',
+    // the easiest way to trigger a synchronous
+    // thrown error in request is a malformed url:
+    endpoint: `1231..;`,
+    sourceMap: `${__dirname}/fixtures/noop.min.js.map`
+  }).then(() => {
+    throw new Error('expected promise to be rejected')
+  }).catch(err => {
+    expect(err).toBeTruthy()
+    expect(err.message).toBe('Invalid URI "1231..;"')
+  })
+})
+
 let server, app
 const createTestServer = () => {
   return new Promise((resolve, reject) => {