diff --git a/requirements.txt b/requirements.txt
index a08725076e..92c67adb14 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -15,6 +15,7 @@ lunr == 0.6.0
 simpleeval <= 1.0
 uritemplate == 4.1.1
 Jinja2 < 3.1
+tzdata
 
 # try to resolve dependency issue in py3.7
 attrs >= 19.2.0