diff --git a/bn.rkt b/bn.rkt
index b4932c3..c759769 100644
--- a/bn.rkt
+++ b/bn.rkt
@@ -7,6 +7,7 @@
 ;;; are updated according to their corresponding update functions.
 ;;; The variables to be updated at each step are given by the mode.
 
+(provide State UpdateFunc Network)
 
 ;;; A state of a Boolean network is a mapping from the variables of the
 ;;; network to their Boolean values.