diff --git a/src/code/unix.lisp b/src/code/unix.lisp
index eea07a7f7828cf8d21d35191adc02954f1a4035d..0fb48d8e5e8941beba659a3957e94118ffcabd9f 100644
--- a/src/code/unix.lisp
+++ b/src/code/unix.lisp
@@ -25,7 +25,7 @@
 ;; Must be set to NIL initially to enable building Lisp!
 (defvar *filename-encoding* nil)
 
-(eval-when (:compile-toplevel)
+(eval-when (:compile-toplevel :load-toplevel :execute)
   (defmacro %name->file (string)
     `(if *filename-encoding*
 	 (string-encode ,string *filename-encoding*)