diff --git a/networks.rkt b/networks.rkt
index 5aa1bfc..38d72f3 100644
--- a/networks.rkt
+++ b/networks.rkt
@@ -944,7 +944,7 @@
 
 ;;; A state TBF is a TBF with named inputs.  A state TBF can be
 ;;; applied to states in an unambiguous ways.
-(struct tbf/state (weights threshold))
+(struct tbf/state (weights threshold) #:transparent)
 
 ;;; Shortcuts for acessing fields of a state/tbf.
 (define tbf/state-w tbf/state-weights)