diff --git a/implementations/racket/preserves/preserves/read-binary.rkt b/implementations/racket/preserves/preserves/read-binary.rkt
index 2b046d1..6edcb1c 100644
--- a/implementations/racket/preserves/preserves/read-binary.rkt
+++ b/implementations/racket/preserves/preserves/read-binary.rkt
@@ -99,10 +99,10 @@
     (define (next-varint) (eof-guard (read-varint in-port)))
 
     (define (next-integer n)
-      (when (zero? n) (return (on-fail "Zero-length integer not permitted")))
-      (define acc0 (next-byte))
-      (define acc (if (< acc0 128) acc0 (- acc0 256)))
-      (for/fold [(acc acc)] [(n (in-range (- n 1)))] (+ (* acc 256) (next-byte))))
+      (cond [(zero? n) 0]
+            [else (define acc0 (next-byte))
+                  (define acc (if (< acc0 128) acc0 (- acc0 256)))
+                  (for/fold [(acc acc)] [(n (in-range (- n 1)))] (+ (* acc 256) (next-byte)))]))
 
     (define (next-items)
       (define pos0 (pos))