diff --git a/src/RedirectMiddleware.php b/src/RedirectMiddleware.php
index 1dd38614f..89c06526b 100644
--- a/src/RedirectMiddleware.php
+++ b/src/RedirectMiddleware.php
@@ -88,6 +88,16 @@ public function checkRedirect(RequestInterface $request, array $options, Respons
         $this->guardMax($request, $response, $options);
         $nextRequest = $this->modifyRequest($request, $options, $response);
 
+        // If authorization is handled by curl, unset it if host is different.
+        if ($request->getUri()->getHost() !== $nextRequest->getUri()->getHost()
+            && defined('\CURLOPT_HTTPAUTH')
+        ) {
+            unset(
+                $options['curl'][\CURLOPT_HTTPAUTH],
+                $options['curl'][\CURLOPT_USERPWD]
+            );
+        }
+
         if (isset($options['allow_redirects']['on_redirect'])) {
             ($options['allow_redirects']['on_redirect'])(
                 $request,
diff --git a/tests/RedirectMiddlewareTest.php b/tests/RedirectMiddlewareTest.php
index bc587c0a2..1e0841a27 100644
--- a/tests/RedirectMiddlewareTest.php
+++ b/tests/RedirectMiddlewareTest.php
@@ -300,6 +300,64 @@ static function (RequestInterface $request) {
         $client->get('http://example.com?a=b', ['auth' => ['testuser', 'testpass']]);
     }
 
+    /**
+     * @testWith ["digest"]
+     *           ["ntlm"]
+     */
+    public function testRemoveCurlAuthorizationOptionsOnRedirect($auth)
+    {
+        if (!defined('\CURLOPT_HTTPAUTH')) {
+            self::markTestSkipped('ext-curl is required for this test');
+        }
+
+        $mock = new MockHandler([
+            new Response(302, ['Location' => 'http://test.com']),
+            static function (RequestInterface $request, $options) {
+                self::assertFalse(
+                    isset($options['curl'][\CURLOPT_HTTPAUTH]),
+                    'curl options still contain CURLOPT_HTTPAUTH entry'
+                );
+                self::assertFalse(
+                    isset($options['curl'][\CURLOPT_USERPWD]),
+                    'curl options still contain CURLOPT_USERPWD entry'
+                );
+                return new Response(200);
+            }
+        ]);
+        $handler = HandlerStack::create($mock);
+        $client = new Client(['handler' => $handler]);
+        $client->get('http://example.com?a=b', ['auth' => ['testuser', 'testpass', $auth]]);
+    }
+
+    /**
+     * @testWith ["digest"]
+     *           ["ntlm"]
+     */
+    public function testNotRemoveCurlAuthorizationOptionsOnRedirect($auth)
+    {
+        if (!defined('\CURLOPT_HTTPAUTH') || !defined('\CURLOPT_USERPWD')) {
+            self::markTestSkipped('ext-curl is required for this test');
+        }
+
+        $mock = new MockHandler([
+            new Response(302, ['Location' => 'http://example.com/2']),
+            static function (RequestInterface $request, $options) {
+                self::assertTrue(
+                    isset($options['curl'][\CURLOPT_HTTPAUTH]),
+                    'curl options does not contain expected CURLOPT_HTTPAUTH entry'
+                );
+                self::assertTrue(
+                    isset($options['curl'][\CURLOPT_USERPWD]),
+                    'curl options does not contain expected CURLOPT_USERPWD entry'
+                );
+                return new Response(200);
+            }
+        ]);
+        $handler = HandlerStack::create($mock);
+        $client = new Client(['handler' => $handler]);
+        $client->get('http://example.com?a=b', ['auth' => ['testuser', 'testpass', $auth]]);
+    }
+
     /**
      * Verifies how RedirectMiddleware::modifyRequest() modifies the method and body of a request issued when
      * encountering a redirect response.