diff --git a/requirements.txt b/requirements.txt
index 7ddd32fa6..332b39378 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -5,3 +5,4 @@ brotlipy==0.7.0; platform_python_implementation == "PyPy"
 unicodedata2==11.0.0; python_version < '3.7' and platform_python_implementation != "PyPy"
 munkres==1.0.10
 zopfli==0.1.4
+fs==2.1.1