diff --git a/src/Symfony/Component/HttpClient/HttpClientTrait.php b/src/Symfony/Component/HttpClient/HttpClientTrait.php
index cf439c6ff0..2d9de605bf 100644
--- a/src/Symfony/Component/HttpClient/HttpClientTrait.php
+++ b/src/Symfony/Component/HttpClient/HttpClientTrait.php
@@ -422,6 +422,10 @@ trait HttpClientTrait
             $url['path'] = '/';
         }
 
+        if ('?' === ($url['query'] ?? '')) {
+            $url['query'] = null;
+        }
+
         return $url;
     }
 
diff --git a/src/Symfony/Component/HttpClient/Tests/HttpClientTraitTest.php b/src/Symfony/Component/HttpClient/Tests/HttpClientTraitTest.php
index 0feccd22b7..d75dc0084a 100644
--- a/src/Symfony/Component/HttpClient/Tests/HttpClientTraitTest.php
+++ b/src/Symfony/Component/HttpClient/Tests/HttpClientTraitTest.php
@@ -44,6 +44,9 @@ class HttpClientTraitTest extends TestCase
         yield ['http://example.com/?a=2&b=b', '.?a=2'];
         yield ['http://example.com/?a=3&b=b', '.', ['a' => 3]];
         yield ['http://example.com/?a=3&b=b', '.?a=0', ['a' => 3]];
+        yield ['http://example.com/', 'http://example.com/', ['a' => null]];
+        yield ['http://example.com/?b=', 'http://example.com/', ['b' => '']];
+        yield ['http://example.com/?b=', 'http://example.com/', ['a' => null, 'b' => '']];
     }
 
     /**