diff --git a/ChangeLog b/ChangeLog
index 956401a2fc..f66890db9c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -911,6 +911,10 @@ Sat May 17 12:15:48 2008  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* file.c (rb_file_s_extname): ditto.
 
+Sat May 17 10:18:44 2008  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* re.c (rb_reg_search): need to free allocated buffer in re_register.
+
 Mon Mar  3 23:34:13 2008  GOTOU Yuuzou  <gotoyuzo@notwork.org>
 
 	* lib/webrick/httpservlet/filehandler.rb: should normalize path
diff --git a/re.c b/re.c
index 6cada9a714..5553d28dba 100644
--- a/re.c
+++ b/re.c
@@ -927,6 +927,7 @@ rb_reg_search(re, str, pos, reverse)
     }
 
     if (result < 0) {
+	re_free_registers(&regs);
 	rb_backref_set(Qnil);
 	return result;
     }
@@ -943,6 +944,7 @@ rb_reg_search(re, str, pos, reverse)
     }
 
     re_copy_registers(RMATCH(match)->regs, &regs);
+    re_free_registers(&regs);
     RMATCH(match)->str = rb_str_new4(str);
     rb_backref_set(match);