diff --git a/networks.rkt b/networks.rkt
index 447c187..cb909f3 100644
--- a/networks.rkt
+++ b/networks.rkt
@@ -254,16 +254,21 @@
     (check-equal? (f s) #f)))
 
 ;;; Build a network from a network form.
-(define (network-form->network bnf)
-  (for/hash ([(x form) bnf])
-    (values x (update-function-form->update-function form))))
+(define (network-form->network nf)
+  (network
+   (for/hash ([(x form) (in-hash (network-form-forms nf))])
+     (values x (update-function-form->update-function form)))
+   (network-form-domains nf)))
 
 (module+ test
   (test-case "network-form->network"
     (define bn (network-form->network
-         (make-hash '((a . (and a b)) (b . (not b))))))
+                (network-form (hash 'a '(and a b)
+                                    'b '(not b))
+                              (hash 'a (#f #t)
+                                    'b (#f #t)))))
     (define s (make-state '((a . #t) (b . #t))))
-    (check-equal? ((hash-ref bn 'a) s) #t)))
+    (check-equal? ((hash-ref (network-functions bn) 'a) s) #t)))
 
 ;;; Build a network from a list of pairs of forms of update functions.
 (define (make-network-from-forms forms)