diff --git a/ChangeLog b/ChangeLog
index d2fdef48c4..d1e7d0f0e2 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Mon Oct  4 07:57:51 2010  NARUSE, Yui  <naruse@ruby-lang.org>
+
+	* cont.c (fiber_memsize): Return size.
+	  Before this change, fiber_memsize always returns 0.
+
 Mon Oct  4 07:16:55 2010  NARUSE, Yui  <naruse@ruby-lang.org>
 
 	* enc/unicode.c (onigenc_unicode_property_name_to_ctype):
diff --git a/cont.c b/cont.c
index 503cc5f475..01e15624da 100644
--- a/cont.c
+++ b/cont.c
@@ -319,7 +319,7 @@ fiber_memsize(const void *ptr)
 	}
 	size += cont_memsize(&fib->cont);
     }
-    return 0;
+    return size;
 }
 
 static void