diff --git a/tests/integration/conftest.py b/tests/integration/conftest.py
index d71f0f89..8a8aebe6 100644
--- a/tests/integration/conftest.py
+++ b/tests/integration/conftest.py
@@ -9,6 +9,7 @@ from pipenv.vendor import delegator
 from pipenv.vendor import requests
 from pipenv.vendor import six
 from pipenv.vendor import toml
+from pytest_pypi.app import prepare_packages as prepare_pypi_packages
 
 if six.PY2:
     class ResourceWarning(Warning):
@@ -30,6 +31,8 @@ def check_internet():
 WE_HAVE_INTERNET = check_internet()
 
 TESTS_ROOT = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+PYPI_VENDOR_DIR = os.path.join(TESTS_ROOT, 'pypi')
+prepare_pypi_packages(PYPI_VENDOR_DIR)
 
 
 def pytest_runtest_setup(item):
@@ -68,7 +71,6 @@ class _PipenvInstance(object):
         os.environ['PIPENV_DONT_USE_PYENV'] = '1'
         os.environ['PIPENV_IGNORE_VIRTUALENVS'] = '1'
         os.environ['PIPENV_VENV_IN_PROJECT'] = '1'
-        os.environ['PYPI_VENDOR_DIR'] = os.path.join(TESTS_ROOT, 'pypi')
         if self.chdir:
             os.chdir(self.path)
         return self
diff --git a/tests/pytest-pypi/pytest_pypi/app.py b/tests/pytest-pypi/pytest_pypi/app.py
index 57a368b8..7ac1bc4b 100644
--- a/tests/pytest-pypi/pytest_pypi/app.py
+++ b/tests/pytest-pypi/pytest_pypi/app.py
@@ -4,9 +4,6 @@ import json
 import requests
 from flask import Flask, redirect, abort, render_template, send_file, jsonify
 
-PYPI_VENDOR_DIR = os.environ.get('PYPI_VENDOR_DIR', './pypi')
-PYPI_VENDOR_DIR = os.path.abspath(PYPI_VENDOR_DIR)
-
 app = Flask(__name__)
 session = requests.Session()
 
@@ -14,41 +11,49 @@ packages = {}
 
 
 class Package(object):
-    """docstring for Package"""
+    """Package represents a collection of releases from one or more directories"""
 
     def __init__(self, name):
         super(Package, self).__init__()
         self.name = name
-        self._releases = []
+        self.releases = {}
+        self._package_dirs = set()
 
     @property
-    def releases(self):
-        r = []
-        for release in self._releases:
-            release = release[len(PYPI_VENDOR_DIR):].replace('\\', '/')
-            r.append(release)
-        return r
+    def json(self):
+        for path in self._package_dirs:
+            try:
+                with open(os.path.join(path, 'api.json')) as f:
+                    return json.load(f)
+            except FileNotFoundError:
+                pass
 
     def __repr__(self):
         return "<Package name={0!r} releases={1!r}".format(self.name, len(self.releases))
 
     def add_release(self, path_to_binary):
-        self._releases.append(path_to_binary)
+        path_to_binary = os.path.abspath(path_to_binary)
+        path, release = os.path.split(path_to_binary)
+        self.releases[release] = path_to_binary
+        self._package_dirs.add(path)
 
 
-def prepare_packages():
-    for root, dirs, files in os.walk(os.path.abspath(PYPI_VENDOR_DIR)):
+def prepare_packages(path):
+    """Add packages in path to the registry."""
+    path = os.path.abspath(path)
+    if not (os.path.exists(path) and os.path.isdir(path)):
+        raise ValueError("{} is not a directory!".format(path))
+    if not (os.path.exists(path) and os.path.isdir(path)):
+        raise ValueError("{} is not a directory!".format(path))
+    for root, dirs, files in os.walk(path):
         for file in files:
             if not file.startswith('.') and not file.endswith('.json'):
-                package_name = root.split(os.path.sep)[-1]
+                package_name = os.path.basename(root)
 
                 if package_name not in packages:
                     packages[package_name] = Package(package_name)
 
-                packages[package_name].add_release(os.path.sep.join([root, file]))
-
-
-prepare_packages()
+                packages[package_name].add_release(os.path.join(root, file))
 
 
 @app.route('/')
@@ -74,22 +79,26 @@ def serve_package(package, release):
     if package in packages:
         package = packages[package]
 
-        for _release in package.releases:
-            if _release.endswith(release):
-                return send_file(os.path.sep.join([PYPI_VENDOR_DIR, _release]))
+        if release in package.releases:
+            return send_file(package.releases[release])
 
     abort(404)
 
+
 @app.route('/pypi/<package>/json')
 def json_for_package(package):
     try:
-        with open(os.path.sep.join([PYPI_VENDOR_DIR, package, 'api.json'])) as f:
-            return jsonify(json.load(f))
+        return jsonify(packages[package].json)
     except Exception:
         pass
 
     r = session.get('https://pypi.org/pypi/{0}/json'.format(package))
     return jsonify(r.json())
 
+
 if __name__ == '__main__':
+    PYPI_VENDOR_DIR = os.environ.get('PYPI_VENDOR_DIR', './pypi')
+    PYPI_VENDOR_DIR = os.path.abspath(PYPI_VENDOR_DIR)
+    prepare_packages(PYPI_VENDOR_DIR)
+
     app.run()
diff --git a/tests/pytest-pypi/pytest_pypi/templates/package.html b/tests/pytest-pypi/pytest_pypi/templates/package.html
index 36e70a88..26ba9eca 100644
--- a/tests/pytest-pypi/pytest_pypi/templates/package.html
+++ b/tests/pytest-pypi/pytest_pypi/templates/package.html
@@ -7,8 +7,8 @@
 <body>
 	<h1>Links for {{ package.name }}</h1>
 	{% for release in package.releases %}
-		<a href="{{ release }}">{{ release }}</a>
+		<a href="/{{ package.name }}/{{ release }}">{{ release }}</a>
 		<br>
 	{% endfor %}
 </body>
-</html>
\ No newline at end of file
+</html>