diff --git a/oni-python.el b/oni-python.el
index 7f3ca7f..f1f310c 100644
--- a/oni-python.el
+++ b/oni-python.el
@@ -4,7 +4,7 @@
 
 ;; Author: Tom Willemse <tom@ryuslash.org>
 ;; Keywords: local
-;; Version: 20190131153854
+;; Version: 20190201004304
 ;; Package-Requires: (company-jedi fill-column-indicator flycheck rainbow-delimiters reformatter)
 
 ;; This program is free software; you can redistribute it and/or modify
@@ -50,7 +50,7 @@ The values are taken from the PEP8 coding standard for Python."
 
 (reformatter-define python-black
   :program "black"
-  :args "-"
+  :args `("--line-length" ,(number-to-string fill-column) "-")
   :lighter ""
   :group 'python-black)