diff --git a/ChangeLog b/ChangeLog
index f6aff7f594..ebaf06afaf 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Wed Sep 24 17:02:14 2008  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* complex.c (Init_Complex), rational.c (Init_Rational): ID_ALLOCATOR
+	  differs from :allocate, and invisible in ruby level.
+
 Wed Sep 24 15:58:52 2008  Yukihiro Matsumoto  <matz@ruby-lang.org>
 
 	* string.c (rb_str_rstrip_bang): removing mixed spaces and nuls at
diff --git a/complex.c b/complex.c
index 23940dc270..dba87d4984 100644
--- a/complex.c
+++ b/complex.c
@@ -1371,17 +1371,10 @@ Init_Complex(void)
     rb_cComplex = rb_define_class(COMPLEX_NAME, rb_cNumeric);
 
     rb_define_alloc_func(rb_cComplex, nucomp_s_alloc);
-    rb_funcall(rb_cComplex, rb_intern("private_class_method"), 1,
-	       ID2SYM(rb_intern("allocate")));
 
 #if 0
-    rb_define_singleton_method(rb_cComplex, "new!", nucomp_s_new_bang, -1);
-    rb_funcall(rb_cComplex, rb_intern("private_class_method"), 1,
-	       ID2SYM(rb_intern("new!")));
-
-    rb_define_singleton_method(rb_cComplex, "new", nucomp_s_new, -1);
-    rb_funcall(rb_cComplex, rb_intern("private_class_method"), 1,
-	       ID2SYM(rb_intern("new")));
+    rb_define_private_method(CLASS_OF(rb_cComplex), "new!", nucomp_s_new_bang, -1);
+    rb_define_private_method(CLASS_OF(rb_cComplex), "new", nucomp_s_new, -1);
 #else
     rb_undef_method(CLASS_OF(rb_cComplex), "new");
 #endif
@@ -1472,9 +1465,7 @@ Init_Complex(void)
 
     rb_define_method(rb_cString, "to_c", string_to_c, 0);
 
-    rb_define_singleton_method(rb_cComplex, "convert", nucomp_s_convert, -1);
-    rb_funcall(rb_cComplex, rb_intern("private_class_method"), 1,
-	       ID2SYM(rb_intern("convert")));
+    rb_define_private_method(CLASS_OF(rb_cComplex), "convert", nucomp_s_convert, -1);
 
     /* --- */
 
diff --git a/rational.c b/rational.c
index 8e77c8aa0a..ad235498ba 100644
--- a/rational.c
+++ b/rational.c
@@ -1488,17 +1488,10 @@ Init_Rational(void)
     rb_cRational = rb_define_class(RATIONAL_NAME, rb_cNumeric);
 
     rb_define_alloc_func(rb_cRational, nurat_s_alloc);
-    rb_funcall(rb_cRational, rb_intern("private_class_method"), 1,
-	       ID2SYM(rb_intern("allocate")));
 
 #if 0
-    rb_define_singleton_method(rb_cRational, "new!", nurat_s_new_bang, -1);
-    rb_funcall(rb_cRational, rb_intern("private_class_method"), 1,
-	       ID2SYM(rb_intern("new!")));
-
-    rb_define_singleton_method(rb_cRational, "new", nurat_s_new, -1);
-    rb_funcall(rb_cRational, rb_intern("private_class_method"), 1,
-	       ID2SYM(rb_intern("new")));
+    rb_define_private_method(CLASS_OF(rb_cRational), "new!", nurat_s_new_bang, -1);
+    rb_define_private_method(CLASS_OF(rb_cRational), "new", nurat_s_new, -1);
 #else
     rb_undef_method(CLASS_OF(rb_cRational), "new");
 #endif
@@ -1574,9 +1567,7 @@ Init_Rational(void)
 
     rb_define_method(rb_cString, "to_r", string_to_r, 0);
 
-    rb_define_singleton_method(rb_cRational, "convert", nurat_s_convert, -1);
-    rb_funcall(rb_cRational, rb_intern("private_class_method"), 1,
-	       ID2SYM(rb_intern("convert")));
+    rb_define_private_method(CLASS_OF(rb_cRational), "convert", nurat_s_convert, -1);
 }
 
 /*