diff --git a/board/gateworks/gw_ventana/gw_ventana.c b/board/gateworks/gw_ventana/gw_ventana.c
index 137f817111d95515239c70edc9b11e14aee96f9b..bce11b24d62ec3f2ad6589f572a9b9c97bd3a1f9 100644
--- a/board/gateworks/gw_ventana/gw_ventana.c
+++ b/board/gateworks/gw_ventana/gw_ventana.c
@@ -1277,7 +1277,7 @@ void ft_board_setup(void *blob, bd_t *bd)
 
 	/* board serial number */
 	fdt_setprop(blob, 0, "system-serial", getenv("serial#"),
-		    strlen(getenv("serial#") + 1));
+		    strlen(getenv("serial#")) + 1);
 
 	/* board (model contains model from device-tree) */
 	fdt_setprop(blob, 0, "board", info->model,