diff --git a/ChangeLog b/ChangeLog
index f2aea85c60..1f136ee90a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Tue Jan 12 20:44:14 2010  Tanaka Akira  <akr@fsij.org>
+
+	* file.c (realpath_internal): call rb_secure.
+
 Tue Jan 12 16:48:46 2010  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* lib/net/http.rb (Net::HTTP.start): options may not be given.
diff --git a/file.c b/file.c
index bc5071ed8d..99435829c9 100644
--- a/file.c
+++ b/file.c
@@ -3173,6 +3173,9 @@ realpath_internal(VALUE path, int strict)
     volatile VALUE unresolved_path;
     char *unresolved_names;
     VALUE loopcheck;
+
+    rb_secure(2);
+
     FilePathValue(path);
     unresolved_path = rb_str_dup_frozen(path);
     unresolved_names = skiproot(RSTRING_PTR(unresolved_path));