diff --git a/requirements_dev.txt b/requirements_dev.txt
index 558a420..c69907f 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -1,4 +1,4 @@
-black
+black==19.3b0
 pylint==2.3.1
 pytest==5.1.2
 pytest-sugar