diff --git a/pd/src/s_inter.c b/pd/src/s_inter.c
index a712dba3a1d75e6927d7423e3dfbcdea4c5f9220..3ee486e46a33515554ae7f55c7cd508f130b2397 100644
--- a/pd/src/s_inter.c
+++ b/pd/src/s_inter.c
@@ -1574,7 +1574,7 @@ int sys_startgui(const char *guidir)
             portbuf,
             "localhost",
             (sys_k12_mode ? "pd-l2ork-k12" : "pd-l2ork"),
-            scriptbuf, pd_this_string, 0);
+            scriptbuf, pd_this_string, NULL);
         if (spawnret < 0)
         {
             perror("spawnl");