diff --git a/typed-racket-lib/typed-racket/base-env/prims-contract.rkt b/typed-racket-lib/typed-racket/base-env/prims-contract.rkt
index 9668205b..739f9408 100644
--- a/typed-racket-lib/typed-racket/base-env/prims-contract.rkt
+++ b/typed-racket-lib/typed-racket/base-env/prims-contract.rkt
@@ -140,6 +140,8 @@
 
 
   (define ((r/t-maker legacy) stx)
+    (unless (unbox typed-context?)
+      (raise-syntax-error #f "only allowed in a typed module" stx))
     (syntax-parse stx
       [(_ lib:expr (~var c (clause legacy #'lib)) ...)
        (when (zero? (syntax-length #'(c ...)))