diff --git a/ChangeLog b/ChangeLog
index 7a32751bb1..72557a12ec 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sat Aug 31 00:25:15 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* include/ruby/encoding.h (rb_{ascii8bit,utf8,usascii}_encindex): get
+	  rid of conflict with macros defined in internal.h.
+
 Fri Aug 30 22:37:57 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* thread_pthread.c (native_thread_init_stack): wait the creator thread
diff --git a/include/ruby/encoding.h b/include/ruby/encoding.h
index 3db70acaf3..ebd9cfd262 100644
--- a/include/ruby/encoding.h
+++ b/include/ruby/encoding.h
@@ -197,9 +197,15 @@ rb_encoding *rb_locale_encoding(void);
 rb_encoding *rb_filesystem_encoding(void);
 rb_encoding *rb_default_external_encoding(void);
 rb_encoding *rb_default_internal_encoding(void);
+#ifndef rb_ascii8bit_encindex
 int rb_ascii8bit_encindex(void);
+#endif
+#ifndef rb_utf8_encindex
 int rb_utf8_encindex(void);
+#endif
+#ifndef rb_usascii_encindex
 int rb_usascii_encindex(void);
+#endif
 int rb_locale_encindex(void);
 int rb_filesystem_encindex(void);
 VALUE rb_enc_default_external(void);