diff --git a/collects/tests/typed-racket/fail/pr13209.rkt b/collects/tests/typed-racket/fail/pr13209.rkt
new file mode 100644
index 00000000..9346a48e
--- /dev/null
+++ b/collects/tests/typed-racket/fail/pr13209.rkt
@@ -0,0 +1,9 @@
+#;
+(exn-pred exn:fail:syntax?)
+#lang typed/racket
+
+(struct: (α) leaf ({value : α}))
+(struct: (α) node ({left : [Tree α]} {right : [Tree α]}))
+
+(define-type (Tree α) (mu Tree (U (leaf α) (node Tree Tree))))
+