diff --git a/src/protocol/protocol.cpp b/src/protocol/protocol.cpp
index 1bfa58b..2673d1d 100644
--- a/src/protocol/protocol.cpp
+++ b/src/protocol/protocol.cpp
@@ -77,7 +77,11 @@ namespace protocol {
     }
 
     void protocol_t::send_data_line(const session_key_t& session_key, const token::string_t& session_token, const string& data_line) {
-        send({"filter-dataline", session_key, session_token, data_line});
+        if(version < "0.5") {
+            send({"filter-dataline", session_token, session_key, data_line});
+        } else {
+            send({"filter-dataline", session_key, session_token, data_line});
+        }
     }
 
     void protocol_t::submit_message(const session_key_t& session_key, const token::string_t& session_token, const vector<string>& header, const vector<string>& body) {