diff --git a/ChangeLog b/ChangeLog
index e376d31429..6d7c3342d5 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,14 @@
+Tue Aug  4 09:33:54 2009  NARUSE, Yui  <naruse@ruby-lang.org>
+
+	* encoding.c (rb_enc_set_base): Add for setting base encoding
+	  with their names. this is internal function.
+
+	* template/encdb.h.tmpl: specify ENC_SET_BASE for second encodings in
+	  each encoding files.
+
+	* enc/encdb.c (rb_enc_set_base): add a declaration.
+	  (ENC_SET_BASE): ditto.
+
 Tue Aug  4 06:30:01 2009  Yukihiro Matsumoto  <matz@ruby-lang.org>
 
 	* hash.c (rb_hash_replace): should copy compare_by_identity status as well.
diff --git a/enc/encdb.c b/enc/encdb.c
index 35f4c93b55..476b55dafe 100644
--- a/enc/encdb.c
+++ b/enc/encdb.c
@@ -13,10 +13,12 @@ int rb_encdb_replicate(const char *alias, const char *orig);
 int rb_encdb_alias(const char *alias, const char *orig);
 int rb_encdb_dummy(const char *name);
 void rb_encdb_declare(const char *name);
+void rb_enc_set_base(const char *name, const char *orig);
 #define ENC_REPLICATE(name, orig) rb_encdb_replicate(name, orig)
 #define ENC_ALIAS(name, orig) rb_encdb_alias(name, orig)
 #define ENC_DUMMY(name) rb_encdb_dummy(name)
 #define ENC_DEFINE(name) rb_encdb_declare(name)
+#define ENC_SET_BASE(name) rb_enc_set_base(name)
 
 void
 Init_encdb(void)
diff --git a/encoding.c b/encoding.c
index 5e54ce7218..49326b6625 100644
--- a/encoding.c
+++ b/encoding.c
@@ -275,6 +275,18 @@ set_base_encoding(int index, rb_encoding *base)
     return enc;
 }
 
+/* for encdb.h
+ * Set base encoding for encodings which are not replicas
+ * but not in their own files.
+ */
+void
+rb_enc_set_base(const char *name, const char *orig)
+{
+    int idx = rb_enc_registered(name);
+    int origidx = rb_enc_registered(orig);
+    set_base_encoding(idx, rb_enc_from_index(origidx));
+}
+
 int
 rb_enc_replicate(const char *name, rb_encoding *encoding)
 {
diff --git a/template/encdb.h.tmpl b/template/encdb.h.tmpl
index e65b651050..4275a4c2f0 100644
--- a/template/encdb.h.tmpl
+++ b/template/encdb.h.tmpl
@@ -34,11 +34,15 @@ encdirs.each do |encdir|
     next if files[fn]
     files[fn] = true
     open(File.join(encdir,fn)) do |f|
-      orig = nil
       name = nil
       f.each_line do |line|
         if (/^OnigEncodingDefine/ =~ line)..(/"(.*?)"/ =~ line)
           if $1
+            if name
+              lines << %[ENC_SET_BASE("#$1", "#{name}");]
+            else
+              name = $1
+            end
             check_duplication(defs, $1, fn, $.)
             encodings << $1
             count += 1