Fix type test in bytevector->hexadecimal.

diff --git a/src/runtime/bytevector.scm b/src/runtime/bytevector.scm
index fd0e55ebce199bf2d75ce7795c9d90084ed41b25..9367a801535333e8415560cf04d1970455521cee 100644 (file)
--- a/src/runtime/bytevector.scm
+++ b/src/runtime/bytevector.scm
@@ -379,7 +379,7 @@ USA.
 (define (bytevector->hexadecimal bytes)
   (define-integrable (hex-char k)
     (string-ref "0123456789ABCDEF" (fix:and k #x0F)))
-  (guarantee string? bytes 'bytevector->hexadecimal)
+  (guarantee bytevector? bytes 'bytevector->hexadecimal)
   (let ((n (bytevector-length bytes))
        (builder (string-builder)))
     (do ((i 0 (fix:+ i 1)))