diff --git a/src/vim9compile.c b/src/vim9compile.c
index ce1ca76..92d1362 100644
--- a/src/vim9compile.c
+++ b/src/vim9compile.c
@@ -3767,7 +3767,8 @@
 	    goto theend;
 
 	stack = &cctx->ctx_type_stack;
-	stacktype = ((type_T **)stack->ga_data)[stack->ga_len - 1];
+	stacktype = stack->ga_len == 0 ? &t_void
+			      : ((type_T **)stack->ga_data)[stack->ga_len - 1];
 	if (idx >= 0 && (is_decl || !has_type))
 	{
 	    lvar = ((lvar_T *)cctx->ctx_locals.ga_data) + idx;