diff --git a/elsa-typed-subr.el b/elsa-typed-subr.el
index bf15283..f59a150 100644
--- a/elsa-typed-subr.el
+++ b/elsa-typed-subr.el
@@ -2,5 +2,6 @@
 (require 'elsa-type-helpers)
 
 (put 'match-string 'elsa-type (elsa-make-type Int -> String? -> String?))
+(put 'last 'elsa-type (elsa-make-type [Mixed] -> Int? -> Cons))
 
 (provide 'elsa-typed-subr)