diff --git a/ChangeLog b/ChangeLog
index 4f6d181b49..6ed8009fa4 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+Tue Sep  6 13:15:44 2011  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* encoding.c (load_encoding): predefined encoding names are safe.
+	  [ruby-dev:44469] [Bug #5279]
+
+	* transcode.c (load_transcoder_entry): ditto.
+
 Tue Sep  6 12:07:10 2011  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* transcode.c: enabled econv newline option.
diff --git a/encoding.c b/encoding.c
index e5bc75b4ef..57af9762e9 100644
--- a/encoding.c
+++ b/encoding.c
@@ -561,6 +561,7 @@ load_encoding(const char *name)
 	else if (ISUPPER(*s)) *s = TOLOWER(*s);
 	++s;
     }
+    FL_UNSET(enclib, FL_TAINT|FL_UNTRUSTED);
     OBJ_FREEZE(enclib);
     ruby_verbose = Qfalse;
     ruby_debug = Qfalse;
diff --git a/test/ruby/test_encoding.rb b/test/ruby/test_encoding.rb
index 6a406ae237..3e2ad5d0d2 100644
--- a/test/ruby/test_encoding.rb
+++ b/test/ruby/test_encoding.rb
@@ -99,4 +99,9 @@ class TestEncoding < Test::Unit::TestCase
     str2 = Marshal.load(Marshal.dump(str2))
     assert_equal(str, str2, '[ruby-dev:38596]')
   end
+
+  def test_unsafe
+    bug5279 = '[ruby-dev:44469]'
+    assert_ruby_status([], '$SAFE=3; "a".encode("utf-16be")', bug5279)
+  end
 end
diff --git a/transcode.c b/transcode.c
index 68ac71755c..482fb6bf17 100644
--- a/transcode.c
+++ b/transcode.c
@@ -370,6 +370,7 @@ load_transcoder_entry(transcoder_entry_t *entry)
         const char *lib = entry->lib;
         size_t len = strlen(lib);
         char path[sizeof(transcoder_lib_prefix) + MAX_TRANSCODER_LIBNAME_LEN];
+        VALUE fn;
 
         entry->lib = NULL;
 
@@ -377,7 +378,10 @@ load_transcoder_entry(transcoder_entry_t *entry)
             return NULL;
         memcpy(path, transcoder_lib_prefix, sizeof(transcoder_lib_prefix) - 1);
         memcpy(path + sizeof(transcoder_lib_prefix) - 1, lib, len + 1);
-        if (!rb_require(path))
+        fn = rb_str_new2(path);
+        FL_UNSET(fn, FL_TAINT|FL_UNTRUSTED);
+        OBJ_FREEZE(fn);
+        if (!rb_require_safe(fn, rb_safe_level()))
             return NULL;
     }