diff --git a/tox.ini b/tox.ini
index 570a61c..bcacef3 100644
--- a/tox.ini
+++ b/tox.ini
@@ -4,12 +4,14 @@ minversion = 3.5
 # hack to prevent .tox from crapping to the project directory
 toxworkdir={env:TOXWORKDIR_BASE:}{toxinidir}/.tox
 
+# useful for tests to know they are running under ci
+# respect user's cache dirs to prevent tox from crapping into project dir
 [testenv]
 passenv =
-    # useful for tests to know they are running under ci
-    CI CI_*
-    # respect user's cache dirs to prevent tox from crapping into project dir
-    MYPY_CACHE_DIR PYTHONPYCACHEPREFIX
+    CI
+    CI_*
+    MYPY_CACHE_DIR
+    PYTHONPYCACHEPREFIX
 
 
 # just the very core tests with minimal dependencies