diff --git a/README.rst b/README.rst
index 92b36b4c..de68cae8 100644
--- a/README.rst
+++ b/README.rst
@@ -123,10 +123,12 @@ used::
     $ ./configure
     $ make
 
-Mac OS X users may need ``--disable-threads`` configure option to
-disable multi threading in nghttpd, nghttpx and h2load to prevent them
-from crashing.  Patch is welcome to make multi threading work on Mac
-OS X platform.
+.. note::
+
+   Mac OS X users may need ``--disable-threads`` configure option to
+   disable multi threading in nghttpd, nghttpx and h2load to prevent
+   them from crashing.  Patch is welcome to make multi threading work
+   on Mac OS X platform.
 
 Building documentation
 ----------------------