--- a/pppd/plugins/pppol2tp/pppol2tp.c
+++ b/pppd/plugins/pppol2tp/pppol2tp.c
@@ -152,6 +152,10 @@ static int setdevname_pppol2tp(char **ar
 	if (pppol2tp_fd_str == NULL)
 		novm("PPPoL2TP FD");
 
+	pppol2tp_fd_str = strdup(*argv);
+	if (pppol2tp_fd_str == NULL)
+		novm("PPPoL2TP FD");
+
 	/* Setup option defaults. Compression options are disabled! */
 
 	modem = 0;
