diff --git a/networks.rkt b/networks.rkt
index 6f5845f..6504632 100644
--- a/networks.rkt
+++ b/networks.rkt
@@ -15,9 +15,10 @@
 
 (provide
  ;; Structures
- (struct-out dynamics)
  (contract-out [struct tbf/state ([weights (hash/c variable? number?)]
-                                  [threshold number?])])
+                                  [threshold number?])]
+               [struct dynamics ([network network?]
+                                 [mode mode?])])
  ;; Functions
  (contract-out [update (-> network? state? (set/c variable? #:kind 'dont-care) state?)]
                [make-state (-> (listof (cons/c symbol? any/c)) state?)]