diff --git a/tox.ini b/tox.ini
index d65ced61..11a72a4b 100644
--- a/tox.ini
+++ b/tox.ini
@@ -10,6 +10,15 @@ max-line-length= 100
 exclude=
 ignore=
 
+[isort]
+force_sort_within_sections=True
+known_third_party=hypothesis,pytest,async_generator,cytoolz,trio_typing,pytest_trio
+multi_line_output=3
+include_trailing_comma=True
+force_grid_wrap=0
+use_parentheses=True
+line_length=88
+
 [testenv]
 deps =
 passenv = CI TRAVIS TRAVIS_*