diff --git a/tox.ini b/tox.ini
index 57ebbc3578d..7969f27a671 100644
--- a/tox.ini
+++ b/tox.ini
@@ -22,7 +22,7 @@ deps = -r{toxinidir}/test-requirements.txt
 # call ie: 'tox -epy27 -- --concurrency=4'
 commands =
   find . -ignore_readdir_race -type f -name "*.pyc" -delete
-  stestr run '{posargs}'
+  stestr run {posargs}
   stestr slowest
 
 whitelist_externals =