diff --git a/functions.rkt b/functions.rkt
index 33084e7..375ecfe 100644
--- a/functions.rkt
+++ b/functions.rkt
@@ -275,6 +275,7 @@
   (01->boolean (apply-tbf tbf (vector-map any->01 inputs))))
 
 (module+ test
-  (define f1 (tbf #(2 -2) 1))
-  (check-equal? (tabulate/boolean (λ (x y) (apply-tbf/boolean f1 (vector x y))))
-                '((#f #f #f) (#f #t #f) (#t #f #t) (#t #t #f))))
+  (test-case "apply-tbf/boolean"
+    (define f1 (tbf #(2 -2) 1))
+    (check-equal? (tabulate/boolean (λ (x y) (apply-tbf/boolean f1 (vector x y))))
+                  '((#f #f #f) (#f #t #f) (#t #f #t) (#t #t #f)))))