diff --git a/setup.cfg b/setup.cfg
index 1293a91f..20333995 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -46,6 +46,7 @@ install_requires =
   psutil
   setuptools
   secretstorage; sys_platform != 'darwin'
+  tzlocal==2.1
   pyobjc-core; sys_platform == 'darwin'
   pyobjc-framework-Cocoa; sys_platform == 'darwin'
   pyobjc-framework-LaunchServices; sys_platform == 'darwin'