diff --git a/hooklib/serial.c b/hooklib/serial.c
index e12bfb6..14d9992 100644
--- a/hooklib/serial.c
+++ b/hooklib/serial.c
@@ -544,12 +544,12 @@ static BOOL WINAPI my_SetCommState(HANDLE fd, const DCB *dcb)
         break;
 
     case RTS_CONTROL_ENABLE:
-        handflow.ControlHandShake |= SERIAL_RTS_CONTROL;
+        handflow.FlowReplace |= SERIAL_RTS_CONTROL;
 
         break;
 
     case RTS_CONTROL_HANDSHAKE:
-        handflow.ControlHandShake |= SERIAL_RTS_HANDSHAKE;
+        handflow.FlowReplace |= SERIAL_RTS_HANDSHAKE;
 
         break;