diff --git a/test-requirements.txt b/test-requirements.txt
index fcdc93c1d..63fa0a9cd 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -1,4 +1,4 @@
-black
+black ; sys_platform != "cygwin"
 coverage[toml]
 ddt >= 1.1.1, != 1.4.3
 mock ; python_version < "3.8"