diff --git a/tox.ini b/tox.ini
index 9e09243e..44f62c76 100644
--- a/tox.ini
+++ b/tox.ini
@@ -20,7 +20,7 @@ commands =
 [testenv:style]
 basepython = python3
 deps =
-  black
+  black==19.10b0
   flake8
   flake8-2020
   flake8-bugbear
@@ -36,7 +36,7 @@ commands =
 [testenv:fix-style]
 basepython = python3
 deps =
-  black
+  black==19.10b0
   pyupgrade
 whitelist_externals =
   bash