diff --git a/software/kumofs/software.cfg b/software/kumofs/software.cfg
index df4234c27e9d5a988a9ed2c1ed539fa673ad4bc1..2ad75ff4af06c8748bba2d72c0137961982ad3b4 100644
--- a/software/kumofs/software.cfg
+++ b/software/kumofs/software.cfg
@@ -16,6 +16,18 @@ extends =
   ../../component/rdiff-backup/buildout.cfg
   ../../component/lxml-python/buildout.cfg
 
+# Use only quite well working sites.
+allow-hosts =
+  *.nexedi.org
+  *.python.org
+  *.sourceforge.net
+  dist.repoze.org
+  effbot.org
+  github.com
+  peak.telecommunity.com
+  psutil.googlecode.com
+  www.dabeaz.com
+
 versions = versions
 
 parts +=
diff --git a/software/memcached/software.cfg b/software/memcached/software.cfg
index f9c56de716d221f855a62e6f47ad67d78735c330..eaa76f1974927c6e906babddd49fcd84f1e2fd61 100644
--- a/software/memcached/software.cfg
+++ b/software/memcached/software.cfg
@@ -14,7 +14,19 @@ extends =
   ../../component/stunnel/buildout.cfg
   ../../component/rdiff-backup/buildout.cfg
   ../../component/lxml-python/buildout.cfg
-  
+
+# Use only quite well working sites.
+allow-hosts =
+  *.nexedi.org
+  *.python.org
+  *.sourceforge.net
+  dist.repoze.org
+  effbot.org
+  github.com
+  peak.telecommunity.com
+  psutil.googlecode.com
+  www.dabeaz.com
+
 versions = versions
 
 parts =