diff --git a/ChangeLog b/ChangeLog
index bcc233f86f..b040be47a5 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Mon Sep  1 14:37:58 2008  NAKAMURA Usaku  <usa@ruby-lang.org>
+
+	* tool/transcode-tblgen.rb: set ERB source filename for error message.
+
 Mon Sep  1 14:37:02 2008  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* enc/depend: transdb.c may not present.
diff --git a/tool/transcode-tblgen.rb b/tool/transcode-tblgen.rb
index 70eb360914..aaf33bee6d 100644
--- a/tool/transcode-tblgen.rb
+++ b/tool/transcode-tblgen.rb
@@ -728,7 +728,9 @@ if VERBOSE_MODE
 end
 
 libs1 = $".dup
-erb_result = ERB.new(src, nil, '%').result(binding)
+erb = ERB.new(src, nil, '%')
+erb.filename = arg
+erb_result = erb.result(binding)
 libs2 = $".dup
 
 libs = libs2 - libs1