diff --git a/implementations/racket/preserves/main.rkt b/implementations/racket/preserves/main.rkt
index 7261581..ac6921f 100644
--- a/implementations/racket/preserves/main.rkt
+++ b/implementations/racket/preserves/main.rkt
@@ -571,7 +571,7 @@
 (define (write-preserve v0 [o (current-output-port)])
   (define-syntax-rule (! fmt arg ...) (fprintf o fmt arg ...))
 
-  (define (write-stringlike-char c)
+  (define (write-stringlike-char c [default (lambda (c) (! "~a" c))])
     (match c
       [#\\ (! "\\\\")]
       [#\u08 (! "\\b")]
@@ -579,7 +579,7 @@
       [#\u0A (! "\\n")]
       [#\u0D (! "\\r")]
       [#\u09 (! "\\t")]
-      [_ (! "~a" c)]))
+      [_ (default c)]))
 
   (define (write-sequence opener comma closer item-writer vs)
     (! "~a" opener)
@@ -627,12 +627,15 @@
        (! "\"")]
       [(? bytes?)
        (! "#\"")
-       (for [(c (in-bytes v))]
-         (match c
+       (for [(b (in-bytes v))]
+         (match b
            [#x22 (! "\\\"")]
-           [#x5C (! "\\\\")]
-           [(? binunescaped?) (! "~a" (integer->char c))]
-           [_ (! "\\x~a" (~a #:min-width 2 #:align 'right #:left-pad-string "0" (number->string c 16)))]))
+           [(? binunescaped?) (write-stringlike-char (integer->char b))]
+           [_ (write-stringlike-char (integer->char b)
+                                     (lambda (c) (! "\\x~a" (~a #:min-width 2
+                                                                #:align 'right
+                                                                #:left-pad-string "0"
+                                                                (number->string b 16)))))]))
        (! "\"")]
       [(? symbol?)
        (define s (symbol->string v))