diff --git a/racketmq/hub/remote-topic.rkt b/racketmq/hub/remote-topic.rkt
index 31e1c4a..e3b4e81 100644
--- a/racketmq/hub/remote-topic.rkt
+++ b/racketmq/hub/remote-topic.rkt
@@ -14,6 +14,13 @@
 (require "../private/util.rkt")
 (require "../protocol.rkt")
 
+(define (set-minimum xs)
+  (for/fold [(i #f)] [(candidate (in-set xs))]
+    (cond [(not candidate) i]
+          [(not i) candidate]
+          [(< candidate i) candidate]
+          [else i])))
+
 (define (remote-topic-main full-topic)
   (define sub-id (random-hex-string 16))
   (log-info "Remote sub endpoint ~a" sub-id)
@@ -29,10 +36,7 @@
   (define/query-set poll-intervals (topic-demand full-topic $i) i)
   (define/query-config min-poll-interval 60)
   (begin/dataflow
-    (define candidate (for/fold [(i #f)] [(candidate (in-set (poll-intervals)))]
-                        (cond [(not i) candidate]
-                              [(< candidate i) candidate]
-                              [else i])))
+    (define candidate (set-minimum (poll-intervals)))
     (poll-interval-seconds (and candidate (max candidate (min-poll-interval)))))
   (begin/dataflow
     (log-info "Poll interval for ~a is now ~a"