diff --git a/tox.ini b/tox.ini
index bcacef3..570a61c 100644
--- a/tox.ini
+++ b/tox.ini
@@ -4,14 +4,12 @@ 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 =
-    CI
-    CI_*
-    MYPY_CACHE_DIR
-    PYTHONPYCACHEPREFIX
+    # 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
 
 
 # just the very core tests with minimal dependencies