diff --git a/tox.ini b/tox.ini
index cef851f..8f38fe7 100644
--- a/tox.ini
+++ b/tox.ini
@@ -5,5 +5,5 @@ envlist = {py27,py36}-pyyaml{3,4}
 deps =
     pyyaml3: PyYAML>=3,<4
     pyyaml4: PyYAML==4.2b4
-commands = python tests.py
+commands = python yacs/tests.py
 
diff --git a/tests.py b/yacs/tests.py
similarity index 100%
rename from tests.py
rename to yacs/tests.py