diff --git a/tests/pytest-pypi/pytest_pypi/app.py b/tests/pytest-pypi/pytest_pypi/app.py
index e8d9431f..18f35102 100644
--- a/tests/pytest-pypi/pytest_pypi/app.py
+++ b/tests/pytest-pypi/pytest_pypi/app.py
@@ -21,7 +21,7 @@ class Package(object):
     def releases(self):
         r = []
         for release in self._releases:
-            release = release[len(PYPI_VENDOR_DIR):]
+            release = release[len(PYPI_VENDOR_DIR):].replace('\\', '/')
             r.append(release)
         return r