diff --git a/tox.ini b/tox.ini
index 6ba6d3b..f53ca99 100644
--- a/tox.ini
+++ b/tox.ini
@@ -9,6 +9,7 @@ deps =
     pytest-cov
     pytest-integration
     pretend
+    setuptools
 setenv =
     PYTESTARGS = --cov=functions_framework --cov-branch --cov-report term-missing --cov-fail-under=100
     windows-latest: PYTESTARGS =