diff --git a/virtualenv/build_virtualenv.sh b/virtualenv/build_virtualenv.sh
index a864a1c..13439fa 100755
--- a/virtualenv/build_virtualenv.sh
+++ b/virtualenv/build_virtualenv.sh
@@ -24,7 +24,7 @@ echo "** activate virtualenv"
 cd $VE
 . bin/activate
 
-pip install --upgrade pip
+pip install pip==1.4.1
 
 echo "** install packages"
 for p in flup "django<1.6" authentic2