diff --git a/src/mark.c b/src/mark.c
index b5f2a7e..d606763 100644
--- a/src/mark.c
+++ b/src/mark.c
@@ -1510,6 +1510,9 @@
     if (rettv_list_alloc(rettv) != OK)
 	return;
 
+    if (in_vim9script() && check_for_opt_buffer_arg(argvars, 0) == FAIL)
+	return;
+
     if (argvars[0].v_type == VAR_UNKNOWN)
     {
 	get_global_marks(rettv->vval.v_list);