diff --git a/src/Symfony/Component/HttpClient/CurlHttpClient.php b/src/Symfony/Component/HttpClient/CurlHttpClient.php
index 83413a23edf45..471f694b4e89f 100644
--- a/src/Symfony/Component/HttpClient/CurlHttpClient.php
+++ b/src/Symfony/Component/HttpClient/CurlHttpClient.php
@@ -220,7 +220,7 @@ public function request(string $method, string $url, array $options = []): Respo
 
         // Prevent curl from sending its default Accept and Expect headers
         foreach (['accept', 'expect'] as $header) {
-            if (!isset($options['normalized_headers'][$header])) {
+            if (!isset($options['normalized_headers'][$header][0])) {
                 $curlopts[CURLOPT_HTTPHEADER][] = $header.':';
             }
         }
@@ -413,7 +413,7 @@ private static function createRedirectResolver(array $options, string $host): \C
                 return 0 !== stripos($h, 'Host:');
             });
 
-            if (isset($options['normalized_headers']['authorization']) || isset($options['normalized_headers']['cookie'])) {
+            if (isset($options['normalized_headers']['authorization'][0]) || isset($options['normalized_headers']['cookie'][0])) {
                 $redirectHeaders['no_auth'] = array_filter($options['headers'], static function ($h) {
                     return 0 !== stripos($h, 'Authorization:') && 0 !== stripos($h, 'Cookie:');
                 });
diff --git a/src/Symfony/Component/HttpClient/HttpClientTrait.php b/src/Symfony/Component/HttpClient/HttpClientTrait.php
index 3fd9814df68f0..ab5f3502f7c00 100644
--- a/src/Symfony/Component/HttpClient/HttpClientTrait.php
+++ b/src/Symfony/Component/HttpClient/HttpClientTrait.php
@@ -57,7 +57,7 @@ private static function prepareRequest(?string $method, ?string $url, array $opt
         }
 
         if (!isset($options['normalized_headers']['accept'])) {
-            $options['normalized_headers']['accept'] = [$options['headers'][] = 'Accept: *'];
+            $options['normalized_headers']['accept'] = [$options['headers'][] = 'Accept: */*'];
         }
 
         if (isset($options['body'])) {
diff --git a/src/Symfony/Component/HttpClient/Tests/HttpClientTestCase.php b/src/Symfony/Component/HttpClient/Tests/HttpClientTestCase.php
index 3d5a70a0a96e5..bc836a7fade1b 100644
--- a/src/Symfony/Component/HttpClient/Tests/HttpClientTestCase.php
+++ b/src/Symfony/Component/HttpClient/Tests/HttpClientTestCase.php
@@ -19,4 +19,32 @@ public function testMaxDuration()
     {
         $this->markTestSkipped('Implemented as of version 4.4');
     }
+
+    public function testAcceptHeader()
+    {
+        $client = $this->getHttpClient(__FUNCTION__);
+
+        $response = $client->request('GET', 'http://localhost:8057');
+        $requestHeaders = $response->toArray();
+
+        $this->assertSame('*/*', $requestHeaders['HTTP_ACCEPT']);
+
+        $response = $client->request('GET', 'http://localhost:8057', [
+            'headers' => [
+                'Accept' => 'foo/bar',
+            ],
+        ]);
+        $requestHeaders = $response->toArray();
+
+        $this->assertSame('foo/bar', $requestHeaders['HTTP_ACCEPT']);
+
+        $response = $client->request('GET', 'http://localhost:8057', [
+            'headers' => [
+                'Accept' => null,
+            ],
+        ]);
+        $requestHeaders = $response->toArray();
+
+        $this->assertArrayNotHasKey('HTTP_ACCEPT', $requestHeaders);
+    }
 }
diff --git a/src/Symfony/Component/HttpClient/Tests/HttpClientTraitTest.php b/src/Symfony/Component/HttpClient/Tests/HttpClientTraitTest.php
index 559f2b62270df..e1636a5d5f84d 100644
--- a/src/Symfony/Component/HttpClient/Tests/HttpClientTraitTest.php
+++ b/src/Symfony/Component/HttpClient/Tests/HttpClientTraitTest.php
@@ -172,7 +172,7 @@ public function provideRemoveDotSegments()
     public function testAuthBearerOption()
     {
         [, $options] = self::prepareRequest('POST', 'http://example.com', ['auth_bearer' => 'foobar'], HttpClientInterface::OPTIONS_DEFAULTS);
-        $this->assertSame(['Accept: *', 'Authorization: Bearer foobar'], $options['headers']);
+        $this->assertSame(['Accept: */*', 'Authorization: Bearer foobar'], $options['headers']);
         $this->assertSame(['Authorization: Bearer foobar'], $options['normalized_headers']['authorization']);
     }
 
diff --git a/src/Symfony/Component/HttpClient/Tests/MockHttpClientTest.php b/src/Symfony/Component/HttpClient/Tests/MockHttpClientTest.php
index 8a3936b442f7a..32b4ebe4485a1 100644
--- a/src/Symfony/Component/HttpClient/Tests/MockHttpClientTest.php
+++ b/src/Symfony/Component/HttpClient/Tests/MockHttpClientTest.php
@@ -36,6 +36,7 @@ protected function getHttpClient(string $testCase): HttpClientInterface
             "SERVER_NAME": "127.0.0.1",
             "REQUEST_URI": "/",
             "REQUEST_METHOD": "GET",
+            "HTTP_ACCEPT": "*/*",
             "HTTP_FOO": "baR",
             "HTTP_HOST": "localhost:8057"
         }';
@@ -113,6 +114,12 @@ protected function getHttpClient(string $testCase): HttpClientInterface
                 $responses[] = $mock;
                 break;
 
+            case 'testAcceptHeader':
+                $responses[] = new MockResponse($body, ['response_headers' => $headers]);
+                $responses[] = new MockResponse(str_replace('*/*', 'foo/bar', $body), ['response_headers' => $headers]);
+                $responses[] = new MockResponse(str_replace('"HTTP_ACCEPT": "*/*",', '', $body), ['response_headers' => $headers]);
+                break;
+
             case 'testResolve':
                 $responses[] = new MockResponse($body, ['response_headers' => $headers]);
                 $responses[] = new MockResponse($body, ['response_headers' => $headers]);