diff --git a/prescheme/scheme48.scm b/prescheme/scheme48.scm
index 9b91146..69e1a48 100644
--- a/prescheme/scheme48.scm
+++ b/prescheme/scheme48.scm
@@ -26,5 +26,4 @@
 (define ascii->char integer->char)
 (define char->ascii char->integer)
 
-;; TODO: requires define-enumeration
-(define unspecific (const #f))
+(define unspecific (if #f #f))