diff --git a/tools/tox_install.sh b/tools/tox_install.sh
deleted file mode 100755
index 7a08b1b6..00000000
--- a/tools/tox_install.sh
+++ /dev/null
@@ -1,44 +0,0 @@
-#!/bin/sh
-
-# Many of neutron's repos suffer from the problem of depending on neutron,
-# but it not existing on pypi.
-
-# This wrapper for tox's package installer will use the existing package
-# if it exists, else use zuul-cloner if that program exists, else grab it
-# from neutron master via a hard-coded URL. That last case should only
-# happen with devs running unit tests locally.
-
-# From the tox.ini config page:
-# install_command=ARGV
-# default:
-# pip install {opts} {packages}
-
-ZUUL_CLONER=/usr/zuul-env/bin/zuul-cloner
-neutron_installed=$(echo "import neutron" | python 2>/dev/null ; echo $?)
-
-set -ex
-
-cwd=$(/bin/pwd)
-
-if [ $neutron_installed -eq 0 ]; then
-    echo "ALREADY INSTALLED" > /tmp/tox_install.txt
-    echo "Neutron already installed; using existing package"
-elif [ -x "$ZUUL_CLONER" ]; then
-    echo "ZUUL CLONER" > /tmp/tox_install.txt
-    cd /tmp
-    export ZUUL_BRANCH=${ZUUL_BRANCH-$BRANCH}
-    $ZUUL_CLONER --cache-dir \
-        /opt/git \
-        git://git.openstack.org \
-        openstack/neutron
-    cd openstack/neutron
-    pip install -e .
-    cd "$cwd"
-else
-    echo "PIP HARDCODE" > /tmp/tox_install.txt
-    pip install -U -egit+https://git.openstack.org/openstack/neutron#egg=neutron
-    pip install -U -egit+https://git.openstack.org/openstack/kuryr#egg=kuryr_lib
-fi
-
-pip install -U $* --process-dependency-links --allow-all-external
-exit $?
diff --git a/tox.ini b/tox.ini
index eab81339..9b4efdf1 100644
--- a/tox.ini
+++ b/tox.ini
@@ -10,7 +10,8 @@ setenv = VIRTUAL_ENV={envdir}
          PYTHONHASHSEED=0
          PYTHONWARNINGS=default::DeprecationWarning
 usedevelop = True
-install_command = {toxinidir}/tools/tox_install.sh {opts} {packages}
+install_command =
+    pip install -U -c{env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt} {opts} {packages}
 deps = -r{toxinidir}/requirements.txt
        -r{toxinidir}/test-requirements.txt
 whitelist_externals = sh