diff --git a/lib/handler/redirect-handler.js b/lib/handler/redirect-handler.js
index 5121cf2263b..2f1995e6a92 100644
--- a/lib/handler/redirect-handler.js
+++ b/lib/handler/redirect-handler.js
@@ -228,7 +228,7 @@ function cleanRequestHeaders (headers, removeContent, unknownOrigin) {
       }
     }
   } else if (headers && typeof headers === 'object') {
-    const entries = headers instanceof Headers ? headers.entries() : Object.entries(headers)
+    const entries = typeof headers[Symbol.iterator] === 'function' ? headers : Object.entries(headers)
     for (const [key, value] of entries) {
       if (!shouldRemoveHeader(key, removeContent, unknownOrigin)) {
         ret.push(key, value)
diff --git a/test/redirect-request.js b/test/redirect-request.js
index 50c8931a5f1..4b7d114319f 100644
--- a/test/redirect-request.js
+++ b/test/redirect-request.js
@@ -13,6 +13,7 @@ const {
   startRedirectingWithQueryParams
 } = require('./utils/redirecting-servers')
 const { createReadable, createReadableStream } = require('./utils/stream')
+const { Headers: UndiciHeaders } = require('..')
 const redirect = undici.interceptors.redirect
 
 for (const factory of [
@@ -227,7 +228,7 @@ for (const factory of [
     await t.completed
   })
 
-  test('should remove Host and request body related headers when following HTTP 303 (Headers)', async t => {
+  test('should remove Host and request body related headers when following HTTP 303 (Global Headers)', async t => {
     t = tspl(t, { plan: 3 })
 
     const server = await startRedirectingServer()
@@ -255,6 +256,62 @@ for (const factory of [
     await t.completed
   })
 
+  test('should remove Host and request body related headers when following HTTP 303 (Undici Headers)', async t => {
+    t = tspl(t, { plan: 3 })
+
+    const server = await startRedirectingServer()
+
+    const { statusCode, headers, body: bodyStream } = await request(t, server, undefined, `http://${server}/303`, {
+      method: 'PATCH',
+      headers: new UndiciHeaders({
+        'Content-Encoding': 'gzip',
+        'X-Foo1': '1',
+        'X-Foo2': '2',
+        'Content-Type': 'application/json',
+        'X-Foo3': '3',
+        Host: 'localhost',
+        'X-Bar': '4'
+      }),
+      maxRedirections: 10
+    })
+
+    const body = await bodyStream.text()
+
+    t.strictEqual(statusCode, 200)
+    t.ok(!headers.location)
+    t.strictEqual(body, `GET /5 :: host@${server} connection@keep-alive x-bar@4 x-foo1@1 x-foo2@2 x-foo3@3`)
+
+    await t.completed
+  })
+
+  test('should remove Host and request body related headers when following HTTP 303 (Maps)', async t => {
+    t = tspl(t, { plan: 3 })
+
+    const server = await startRedirectingServer()
+
+    const { statusCode, headers, body: bodyStream } = await request(t, server, undefined, `http://${server}/303`, {
+      method: 'PATCH',
+      headers: new Map([
+        ['Content-Encoding', 'gzip'],
+        ['X-Foo1', '1'],
+        ['X-Foo2', '2'],
+        ['Content-Type', 'application/json'],
+        ['X-Foo3', '3'],
+        ['Host', 'localhost'],
+        ['X-Bar', '4']
+      ]),
+      maxRedirections: 10
+    })
+
+    const body = await bodyStream.text()
+
+    t.strictEqual(statusCode, 200)
+    t.ok(!headers.location)
+    t.strictEqual(body, `GET /5 :: host@${server} connection@keep-alive x-foo1@1 x-foo2@2 x-foo3@3 x-bar@4`)
+
+    await t.completed
+  })
+
   test('should follow redirection after a HTTP 307', async t => {
     t = tspl(t, { plan: 3 })