diff --git a/src/vim9execute.c b/src/vim9execute.c
index ddc20bc..7c8f779 100644
--- a/src/vim9execute.c
+++ b/src/vim9execute.c
@@ -829,6 +829,7 @@
 	// Check the type of the list items.
 	tv = STACK_TV_BOT(-1);
 	if (ufunc->uf_va_type != NULL
+		&& ufunc->uf_va_type != &t_any
 		&& ufunc->uf_va_type->tt_member != &t_any
 		&& tv->vval.v_list != NULL)
 	{