diff --git a/ChangeLog b/ChangeLog
index 5b65e7c51d..e8a1afba0d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Sat Feb  8 15:11:21 2014  Tanaka Akira  <akr@fsij.org>
+
+	* io.c (SMALLBUF): Unused macro removed.
+
 Fri Feb  7 23:37:49 2014  Tanaka Akira  <akr@fsij.org>
 
 	* lib/resolv.rb: Ignore name servers which cause EAFNOSUPPORT on
diff --git a/io.c b/io.c
index 1d9f87eb5f..3931a4549a 100644
--- a/io.c
+++ b/io.c
@@ -2208,8 +2208,6 @@ rb_io_bufread(VALUE io, void *buf, size_t size)
     return (ssize_t)io_bufread(buf, (long)size, fptr);
 }
 
-#define SMALLBUF 100
-
 static long
 remain_size(rb_io_t *fptr)
 {