diff --git a/extlib/benz b/extlib/benz
index 3a7fb12b..ac638daa 160000
--- a/extlib/benz
+++ b/extlib/benz
@@ -1 +1 @@
-Subproject commit 3a7fb12b2f30986c5dac1b9379d660e491b0f27e
+Subproject commit ac638daa2b4987f199e06a41bc11f23864bd6b97
diff --git a/piclib/picrin/base.scm b/piclib/picrin/base.scm
index cb2a3f8d..4235938c 100644
--- a/piclib/picrin/base.scm
+++ b/piclib/picrin/base.scm
@@ -49,7 +49,12 @@
 
   (export char?
           char->integer
-          integer->char)
+          integer->char
+          char=?
+          char<?
+          char>?
+          char<=?
+          char>=?)
 
   (export number?
           complex?
diff --git a/piclib/scheme/base.scm b/piclib/scheme/base.scm
index 28119e41..4a0778f0 100644
--- a/piclib/scheme/base.scm
+++ b/piclib/scheme/base.scm
@@ -354,16 +354,6 @@
 
   ;; 6.6. Characters
 
-  (define-macro (define-char-transitive-predicate name op)
-    `(define (,name . cs)
-       (apply ,op (map char->integer cs))))
-
-  (define-char-transitive-predicate char=? =)
-  (define-char-transitive-predicate char<? <)
-  (define-char-transitive-predicate char>? >)
-  (define-char-transitive-predicate char<=? <=)
-  (define-char-transitive-predicate char>=? >=)
-
   (export char?
           char->integer
           integer->char