diff --git a/ChangeLog b/ChangeLog
index 2cb53a1a1b..cca7038542 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Thu Jun  6 13:57:06 2013  Narihiro Nakamura  <authornari@gmail.com>
+
+	* ext/objspace/object_tracing.c: allocation_info function isn't
+	  called by any other file.
+
 Thu Jun  6 09:41:00 2013  Kenta Murata  <mrkn@cookpad.com>
 
 	* numeric.c (num_quo): should return a Float for a Float argument.
diff --git a/ext/objspace/object_tracing.c b/ext/objspace/object_tracing.c
index 88f6ecced9..2b98383105 100644
--- a/ext/objspace/object_tracing.c
+++ b/ext/objspace/object_tracing.c
@@ -163,7 +163,7 @@ trace_object_allocations(VALUE objspace)
     return rb_ensure(rb_yield, Qnil, stop_trace_object_allocations, (VALUE)&arg);
 }
 
-struct allocation_info *
+static struct allocation_info *
 allocation_info(VALUE obj)
 {
     if (traceobj_arg) {