diff --git a/ansi-tests/values.lsp b/ansi-tests/values.lsp
index 39fb28398a49bcc5e81b35bfd92f39157e13dd00..a2a355cd9b7b0eff2b93c14d00d2f4a8e0471de3 100644
--- a/ansi-tests/values.lsp
+++ b/ansi-tests/values.lsp
@@ -37,7 +37,7 @@
   1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19)
 
 (deftest values.20
-  (let (a b c d e f)
+  (let ((a t) (b t) (c t) (d t) (e t) (f t))
     (setf (values a (values b c) (values d) (values e f)) (values 0 1 2 3 4 5 6))
     (list a b c d e f))
   (0 1 nil 2 3 nil))