diff --git a/lib/contracts/blockchain.js b/lib/contracts/blockchain.js
index bffb3baa..1b2fdadc 100644
--- a/lib/contracts/blockchain.js
+++ b/lib/contracts/blockchain.js
@@ -265,7 +265,6 @@ class Blockchain {
         if (self.contractsConfig.deployment.type === 'ws') {
           options.headers = {
             'Sec-WebSocket-Version': 13,
-            'Sec-WebSocket-Key': 'h1wEoI9sbNmg4FR0OWRpKw==',
             Connection: 'Upgrade',
             Upgrade: 'websocket',
             'Sec-WebSocket-Extensions': 'permessage-deflate; client_max_window_bits',