diff --git a/src/popupwin.c b/src/popupwin.c
index d86c6c0..59bdf86 100644
--- a/src/popupwin.c
+++ b/src/popupwin.c
@@ -1851,13 +1851,13 @@
     int		nr;
     int		i;
 
-    if (in_vim9script()
-	    && (check_for_string_or_number_or_list_arg(argvars, 0) == FAIL
-		|| check_for_dict_arg(argvars, 1) == FAIL))
-	return NULL;
-
     if (argvars != NULL)
     {
+	if (in_vim9script()
+		&& (check_for_string_or_number_or_list_arg(argvars, 0) == FAIL
+		    || check_for_dict_arg(argvars, 1) == FAIL))
+	    return NULL;
+
 	// Check that arguments look OK.
 	if (argvars[0].v_type == VAR_NUMBER)
 	{