diff --git a/stress.rkt b/stress.rkt
index bb65418..8bb2ffc 100644
--- a/stress.rkt
+++ b/stress.rkt
@@ -17,7 +17,10 @@
   (vector-set! latencies latency-pos ms)
   (set! latency-pos (modulo (+ latency-pos 1) (vector-length latencies)))
   (when (zero? latency-pos)
-    (for-each display (list ";; Mean latency "(/ (for/sum ((i latencies)) i)
+    (for-each display (list ";; Mean latency "(/ (for/fold
+						     ((sum 0))
+						     ((i latencies))
+						   (+ sum i))
 						 (vector-length latencies))"ms\n"))))
 
 (define (stress hostname port-number count rate)