diff --git a/syndicate/smart-pattern.rkt b/syndicate/smart-pattern.rkt
index 8ed2ae3..4855b73 100644
--- a/syndicate/smart-pattern.rkt
+++ b/syndicate/smart-pattern.rkt
@@ -24,13 +24,12 @@
 (require syndicate/schemas/dataspacePatterns)
 
 (define (items->entries pats)
-  (define-values (entries max-i)
-    (for/fold [(entries (hash)) (max-i #f)]
-              [(i (in-naturals)) (p (in-list pats))]
-      (values (if (Pattern-discard? p) entries (hash-set entries i p))
-              i)))
-  (if (and max-i (not (hash-has-key? entries max-i)))
-      (hash-set entries max-i (Pattern-discard))
+  (define npats (length pats))
+  (define entries
+    (for/fold [(entries (hash))] [(i (in-naturals)) (p (in-list pats))]
+      (if (Pattern-discard? p) entries (hash-set entries i p))))
+  (if (and (positive? npats) (not (hash-has-key? entries (- npats 1))))
+      (hash-set entries (- npats 1) (Pattern-discard))
       entries))
 
 (define (entries->items entries on-missing)