diff --git a/conf/squid.conf b/conf/squid.conf
index 0361eef..52e1418 100644
--- a/conf/squid.conf
+++ b/conf/squid.conf
@@ -25,6 +25,7 @@ acl Safe_ports port 777		# multiling http
 acl CONNECT method CONNECT
 
 #
+http_upgrade_request_protocols OTHER allow all
 # Recommended minimum Access Permission configuration:
 #
 acl intermediate_fetching transaction_initiator certificate-fetching