diff --git a/implementations/racket/preserves/preserves/write-text.rkt b/implementations/racket/preserves/preserves/write-text.rkt
index a0381a1..d7f94f3 100644
--- a/implementations/racket/preserves/preserves/write-text.rkt
+++ b/implementations/racket/preserves/preserves/write-text.rkt
@@ -155,7 +155,7 @@
       [(? symbol?)
        (define s (symbol->string v))
        ;; FIXME: This regular expression is conservatively correct, but Anglo-chauvinistic.
-       (if (regexp-match #px"[a-zA-Z~!$%^&*?_=+/.][-a-zA-Z~!$%^&*?_=+/.0-9]*" s)
+       (if (regexp-match #px"^[a-zA-Z~!$%^&*?_=+/.][-a-zA-Z~!$%^&*?_=+/.0-9]*$" s)
            (! "~a" s)
            (begin (! "|")
                   (for [(c (in-string s))]