diff --git a/requirements/dev.in b/requirements/dev.in
index 731ed01e1af84c1be4f8cb4402535866e70e6a82..2fc77a07502a5b9b8a3ccfb93c143f5f3e95b7bb 100644
--- a/requirements/dev.in
+++ b/requirements/dev.in
@@ -43,3 +43,5 @@ numpy>=1.20.1
 pandas>=1.1.0
 scipy>=1.5.0
 StatisticalDiagrams>=20.5
+chardet==3.0.4
+pytz<2021.0,>=2020.1