diff --git a/collects/typed-racket/base-env/base-env.rkt b/collects/typed-racket/base-env/base-env.rkt
index 397893ef85..626b7d78b9 100644
--- a/collects/typed-racket/base-env/base-env.rkt
+++ b/collects/typed-racket/base-env/base-env.rkt
@@ -250,7 +250,7 @@
 [boolean=? (B B . -> . B)]
 [symbol=? (Sym Sym . -> . B)]
 [false? (make-pred-ty (-val #f))]
-
+[xor (-> Univ Univ Univ)]