diff --git a/src/Symfony/Component/HttpClient/Response/ResponseTrait.php b/src/Symfony/Component/HttpClient/Response/ResponseTrait.php
index 80894ffb0103..8d4fe59ae687 100644
--- a/src/Symfony/Component/HttpClient/Response/ResponseTrait.php
+++ b/src/Symfony/Component/HttpClient/Response/ResponseTrait.php
@@ -359,8 +359,9 @@ public static function stream(iterable $responses, float $timeout = null): \Gene
                                 continue;
                             }
 
-                            $response->offset += \strlen($chunk);
+                            $chunkLen = \strlen($chunk);
                             $chunk = new DataChunk($response->offset, $chunk);
+                            $response->offset += $chunkLen;
                         } elseif (null === $chunk) {
                             $e = $multi->handlesActivity[$j][0];
                             unset($responses[$j], $multi->handlesActivity[$j]);