diff --git a/psiphon/common/protocol/protocol.go b/psiphon/common/protocol/protocol.go
index b1b0e7f0b..5d9cd5c27 100644
--- a/psiphon/common/protocol/protocol.go
+++ b/psiphon/common/protocol/protocol.go
@@ -391,6 +391,7 @@ func TunnelProtocolRequiresTLS12SessionTickets(protocol string) bool {
 }
 
 func TunnelProtocolRequiresTLS13Support(protocol string) bool {
+	protocol = TunnelProtocolMinusInproxy(protocol)
 	return protocol == TUNNEL_PROTOCOL_TLS_OBFUSCATED_SSH
 }