diff --git a/foreign/c/pointer.scm b/foreign/c/pointer.scm
index e7a7fee..80519df 100644
--- a/foreign/c/pointer.scm
+++ b/foreign/c/pointer.scm
@@ -101,7 +101,7 @@
   (kawa #t) ; FIXME
   (chibi #t)
   (gauche (define c-null? pointer-null?))
-  #;(mosh (define c-null?
+  (mosh (define c-null?
           (lambda (pointer) (and (c-bytevector? pointer)
                                  (= (pointer->integer pointer) 0)))))
   (else (define c-null?