diff --git a/tox.ini b/tox.ini
index 9d058cf988..eb653b686b 100644
--- a/tox.ini
+++ b/tox.ini
@@ -33,7 +33,7 @@ passenv =
 
 [testenv:functional]
 setenv =
-  TEST_PATH = ./glance/tests/functional
+  OS_TEST_PATH = ./glance/tests/functional
 # TODO(stephenfin): Remove once we bump our upper-constraint to SQLAlchemy 2.0
   SQLALCHEMY_WARN_20=1
 commands = stestr run {posargs}