diff --git a/tox.ini b/tox.ini
index 75acf02..a050a5c 100644
--- a/tox.ini
+++ b/tox.ini
@@ -60,7 +60,7 @@ setenv =
     PYTHON=coverage run --source monasca_transform --parallel-mode
 commands =
     find monasca_transform -type f -name "*.pyc" -delete
-    stestr run '{posargs}'
+    stestr run {posargs}
     coverage combine
     coverage html -d cover
     coverage xml -o cover/coverage.xml