diff --git a/ChangeLog b/ChangeLog
index f86109ce59..eecd4608b9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Wed Jun 24 15:02:29 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* parse.y (parser_set_encode): show the erred file name instead of
+	  the file that requires it.  [ruby-core:24006]
+
 Wed Jun 24 11:41:20 2009  Akinori MUSHA  <knu@iDaemons.org>
 
 	* misc/ruby-style.el: It is too late to set c-file-style in
diff --git a/parse.y b/parse.y
index 1b1636ea43..a044a93408 100644
--- a/parse.y
+++ b/parse.y
@@ -6066,13 +6066,23 @@ parser_set_encode(struct parser_params *parser, const char *name)
 {
     int idx = rb_enc_find_index(name);
     rb_encoding *enc;
+    VALUE excargs[3];
 
     if (idx < 0) {
-	rb_raise(rb_eArgError, "unknown encoding name: %s", name);
+	VALUE rb_make_backtrace(void);
+	VALUE rb_make_exception(int, VALUE*);
+
+	excargs[1] = rb_sprintf("unknown encoding name: %s", name);
+      error:
+	excargs[0] = rb_eArgError;
+	excargs[2] = rb_make_backtrace();
+	rb_ary_unshift(excargs[2], rb_sprintf("%s:%d", ruby_sourcefile, ruby_sourceline));
+	rb_exc_raise(rb_make_exception(3, excargs));
     }
     enc = rb_enc_from_index(idx);
     if (!rb_enc_asciicompat(enc)) {
-	rb_raise(rb_eArgError, "%s is not ASCII compatible", rb_enc_name(enc));
+	excargs[1] = rb_sprintf("%s is not ASCII compatible", rb_enc_name(enc));
+	goto error;
     }
     parser->enc = enc;
 }