diff --git a/zonedb.rkt b/zonedb.rkt
index c1381e9..8ad3419 100644
--- a/zonedb.rkt
+++ b/zonedb.rkt
@@ -9,6 +9,7 @@
 
 (provide incorporate-rr
 	 compile-zone-db
+	 compiled-zone?
 	 in-bailiwick?
 	 set-filter
 	 filter-by-type
@@ -32,6 +33,9 @@
 (define (compile-zone-db rrs)
   (foldl incorporate-rr (make-immutable-hash) rrs))
 
+(define (compiled-zone? z)
+  (hash? z)) ;; hm
+
 ;; in-bailiwick? : DomainName RR -> Boolean
 ;; Answers #t iff dn falls within the bailiwick of the zone with
 ;; origin rr.