diff --git a/src/serial.c b/src/serial.c
index f6c1b67d7..9d580a95f 100644
--- a/src/serial.c
+++ b/src/serial.c
@@ -732,7 +732,7 @@ int HAMLIB_API serial_flush(hamlib_port_t *p)
 
 #ifdef __WIN32__
     struct termios_list *index;
-    index = win32_serial_find_port(fd);
+    index = win32_serial_find_port(p->fd);
 
     if (!index)
     {