diff --git a/system/HTTP/CURLRequest.php b/system/HTTP/CURLRequest.php
index 0728b5be08fc..8a9598b92e8e 100644
--- a/system/HTTP/CURLRequest.php
+++ b/system/HTTP/CURLRequest.php
@@ -543,7 +543,7 @@ protected function applyMethod(string $method, array $curl_options): array
 		if ($method === 'PUT' || $method === 'POST')
 		{
 			// See http://tools.ietf.org/html/rfc7230#section-3.3.2
-			if (is_null($this->getHeader('content-length')))
+			if (is_null($this->getHeader('content-length')) && ! isset($this->config['multipart']))
 			{
 				$this->setHeader('Content-Length', '0');
 			}