diff --git a/src/Transport/Socket.php b/src/Transport/Socket.php
index 8ec77691..7028c51c 100644
--- a/src/Transport/Socket.php
+++ b/src/Transport/Socket.php
@@ -85,7 +85,7 @@ public function request($method, UriInterface $uri, $data = null, array $headers
 		}
 
 		// Configure protocol version, use transport's default if not set otherwise.
-		$protocolVersion = $this->getOption('protocolVersion', '1.0');
+		$protocolVersion = $this->getOption('protocolVersion', '1.1');
 
 		// Build the request payload.
 		$request   = [];