diff --git a/buildout/README-2.12.txt b/buildout/README-2.12.txt
index 1c500809d6ddc09cef72171e9b465aa86ccb153b..ed97cd3aa5c7005f41c457320682df7108340c61 100644
--- a/buildout/README-2.12.txt
+++ b/buildout/README-2.12.txt
@@ -46,6 +46,9 @@ And run it:
 
   $ python2.6 -S bootstrap.py -c buildout-2.12.cfg
 
+WARNING: please read "Troubleshooting" section bellow, you may need to
+unset environment variables in your GNU/Linux distribution
+
 If curl or wget are available, it can be done in one line:
 
 in case of curl: