diff --git a/requirements-dev.txt b/requirements-dev.txt
index c75220b80..ca18bf4ce 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -18,3 +18,4 @@ pytest-faulthandler<2.0; platform_python_implementation == "PyPy"
 pytest-timeout
 feedparser
 python-hglib
+flake8
\ No newline at end of file