diff --git a/pkgs/racket-test/tests/units/test-unit-contracts.rkt b/pkgs/racket-test/tests/units/test-unit-contracts.rkt
index 2113074191..904a1175fa 100644
--- a/pkgs/racket-test/tests/units/test-unit-contracts.rkt
+++ b/pkgs/racket-test/tests/units/test-unit-contracts.rkt
@@ -705,6 +705,24 @@
 (test-contract-error "m4" "f" "not an x"
   (m4:f 3))
 
+(module m4:f racket
+  (define-signature foo^ (x? (contracted [f (-> x? boolean?)])))
+
+  (define-unit U@
+    (import)
+    (export foo^)
+    (define (x? x) #f)
+    (define (f x) (x? x)))
+
+  (define-values/invoke-unit U@ (import) (export [prefix f: foo^]))
+  
+  (provide f:f f:x?))
+
+(require (prefix-in m4: 'm4:f))
+
+(test-contract-error "m4:f" "f:f" "not an f:x"
+  (m4:f:f 3))
+
 (require (prefix-in m3: 'm3))
 
 (test-contract-error top-level "build-toys" "not a integer"
diff --git a/racket/collects/racket/private/unit-contract.rkt b/racket/collects/racket/private/unit-contract.rkt
index f08de1081d..067f17462d 100644
--- a/racket/collects/racket/private/unit-contract.rkt
+++ b/racket/collects/racket/private/unit-contract.rkt
@@ -54,7 +54,7 @@
                                                #`(vector-ref #,v #,index)))))
     (with-syntax ((((eloc ...) ...)
                    (for/list ([target-sig import-sigs])
-                     (let ([rename-bindings (get-member-bindings def-table target-sig #`(blame-positive #,blame-id))])
+                     (let ([rename-bindings (get-member-bindings def-table target-sig #`(blame-positive #,blame-id) #f)])
                        (for/list ([target-int/ext-name (in-list (car target-sig))]
                                   [sig-ctc (in-list (cadddr target-sig))])
                          (let* ([var (car target-int/ext-name)]
diff --git a/racket/collects/racket/private/unit-utils.rkt b/racket/collects/racket/private/unit-utils.rkt
index 7d8f6eb497..27e879b67c 100644
--- a/racket/collects/racket/private/unit-utils.rkt
+++ b/racket/collects/racket/private/unit-utils.rkt
@@ -28,8 +28,9 @@
 (define-syntax-rule (equal-hash-table [k v] ...)
   (make-immutable-hash (list (cons k v) ...)))
 
-(define-for-syntax (get-member-bindings member-table sig pos)
+(define-for-syntax (get-member-bindings member-table sig pos bind?)
   (for/list ([i (in-list (map car (car sig)))]
+             [ix (in-list (map cdr (car sig)))]
              [c (in-list (cadddr sig))])
     (let ([add-ctc
              (λ (v stx)
@@ -39,7 +40,7 @@
                            (contract c-stx (car v/c) (cdr v/c) #,pos
                                      (quote #,v) (quote-syntax #,v))))
                      #`(#,stx)))])
-      #`[#,i
+      #`[#,(if bind? ix i)
          (make-set!-transformer
           (λ (stx)
             (syntax-case stx (set!)
diff --git a/racket/collects/racket/unit.rkt b/racket/collects/racket/unit.rkt
index 6dbbb48e14..816935c531 100644
--- a/racket/collects/racket/unit.rkt
+++ b/racket/collects/racket/unit.rkt
@@ -1252,7 +1252,8 @@
                                 [ctc (bound-identifier-mapping-get ctc-table var)]
                                 [rename-bindings (get-member-bindings def-table
                                                                       (bound-identifier-mapping-get sig-table var)
-                                                                      #'(current-contract-region))])
+                                                                      #'(current-contract-region)
+                                                                      #t)])
                            (with-syntax ([ctc-stx (if ctc (syntax-property
                                                            #`(letrec-syntax #,rename-bindings #,ctc)
                                                            'inferred-name var)
@@ -1732,7 +1733,7 @@
                      (((wrap-code ...) ...)
                       (map (λ (os ov tbs)
                              (define rename-bindings 
-                               (get-member-bindings def-table os #'(quote-module-name)))
+                               (get-member-bindings def-table os #'(quote-module-name) #t))
                              (map (λ (tb i v c)
                                     (if c
                                         (with-syntax ([ctc-stx