diff --git a/requirements.txt b/requirements.txt
index e801619..46c1ce1 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -12,3 +12,4 @@ oslo.log>=3.30.0 # Apache-2.0
 python-keystoneclient!=1.8.0,>=1.6.0
 python-swiftclient>=2.2.0
 python-troveclient>=1.2.0
+horizon>=13.0.0  # Apache-2.0
diff --git a/tools/tox_install.sh b/tools/tox_install.sh
deleted file mode 100755
index 7890956..0000000
--- a/tools/tox_install.sh
+++ /dev/null
@@ -1,65 +0,0 @@
-#!/usr/bin/env bash
-
-# 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
-BRANCH_NAME=master
-GIT_BASE=${GIT_BASE:-https://git.openstack.org/}
-
-install_project() {
-    local project=$1
-    local branch=${2:-$BRANCH_NAME}
-    local module_name=${project//-/_}
-
-    set +e
-    project_installed=$(echo "import $module_name" | python 2>/dev/null ; echo $?)
-    set -e
-
-    if [ $project_installed -eq 0 ]; then
-        echo "ALREADY INSTALLED" > /tmp/tox_install.txt
-        echo "$project already installed; using existing package"
-    elif [ -x "$ZUUL_CLONER" ]; then
-        echo "ZUUL CLONER" > /tmp/tox_install.txt
-        # Make this relative to current working directory so that
-        # git clean can remove it. We cannot remove the directory directly
-        # since it is referenced after $install_cmd -e
-        mkdir -p .tmp
-        PROJECT_DIR=$(/bin/mktemp -d -p $(pwd)/.tmp)
-        pushd $PROJECT_DIR
-        $ZUUL_CLONER --cache-dir \
-            /opt/git \
-            --branch $branch \
-            http://git.openstack.org \
-            openstack/$project
-        cd openstack/$project
-        $install_cmd -e .
-        popd
-    else
-        echo "PIP HARDCODE" > /tmp/tox_install.txt
-        local GIT_REPO="$GIT_BASE/openstack/$project"
-        SRC_DIR="$VIRTUAL_ENV/src/$project"
-        git clone --depth 1 --branch $branch $GIT_REPO $SRC_DIR
-        $install_cmd -U -e $SRC_DIR
-    fi
-}
-
-set -e
-
-install_cmd="pip install -c$1"
-shift
-
-install_project horizon
-
-$install_cmd -U $*
-exit $?
diff --git a/tox.ini b/tox.ini
index f324293..355ffc4 100644
--- a/tox.ini
+++ b/tox.ini
@@ -5,10 +5,11 @@ skipsdist = True
 
 [testenv]
 usedevelop = True
-install_command = {toxinidir}/tools/tox_install.sh {env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt} {opts} {packages}
+install_command = pip install {opts} {packages}
 setenv =
    VIRTUAL_ENV={envdir}
-deps = -r{toxinidir}/requirements.txt
+deps = -c{env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt}
+       -r{toxinidir}/requirements.txt
        -r{toxinidir}/test-requirements.txt
 commands = /bin/bash run_tests.sh -N --no-pep8 {posargs}