diff --git a/xenomorph/xenomorph/redo/helper.rkt b/xenomorph/xenomorph/redo/helper.rkt
index 239693f6..b3594a05 100644
--- a/xenomorph/xenomorph/redo/helper.rkt
+++ b/xenomorph/xenomorph/redo/helper.rkt
@@ -8,16 +8,7 @@
   (cond
     [(bytes? arg) (open-input-bytes arg)]
     [(input-port? arg) arg]
-    [else (raise-argument-error '->port "byte string or input port" arg)]))
-
-(define (reverse-bytes bstr) (apply bytes (reverse (bytes->list bstr))))
-
-(define (unsigned->signed uint bits)
-  (define most-significant-bit-mask (arithmetic-shift 1 (sub1 bits)))
-  (- (bitwise-xor uint most-significant-bit-mask) most-significant-bit-mask))
-
-(define (signed->unsigned sint bits)
-  (bitwise-and sint (arithmetic-shift 1 bits)))
+    [else (raise-argument-error '->input-port "byte string or input port" arg)]))
 
 (define (dump x)
   (cond
diff --git a/xenomorph/xenomorph/redo/number.rkt b/xenomorph/xenomorph/redo/number.rkt
index 3e004760..3e9db853 100644
--- a/xenomorph/xenomorph/redo/number.rkt
+++ b/xenomorph/xenomorph/redo/number.rkt
@@ -7,6 +7,17 @@ approximates
 https://github.com/mbutterick/restructure/blob/master/src/Number.coffee
 |#
 
+(define (unsigned->signed uint bits)
+  (define most-significant-bit-mask (arithmetic-shift 1 (sub1 bits)))
+  (- (bitwise-xor uint most-significant-bit-mask) most-significant-bit-mask))
+
+(define (signed->unsigned sint bits)
+  (bitwise-and sint (arithmetic-shift 1 bits)))
+
+(define (reverse-bytes bstr)
+  (apply bytes
+         (for/list ([b (in-bytes bstr (sub1 (bytes-length bstr)) -1 -1)])
+           b)))
 
 (define (exact-if-possible x) (if (integer? x) (inexact->exact x) x))