diff --git a/tox.ini b/tox.ini
index f787b1f46..dbb27b471 100644
--- a/tox.ini
+++ b/tox.ini
@@ -5,7 +5,7 @@ envlist = py35,py27,pep8
 
 [testenv]
 usedevelop = True
-install_command = pip install -U {opts} {packages}
+install_command = pip install {opts} {packages}
 setenv =
    VIRTUAL_ENV={envdir}
    LANG=en_US.UTF-8