diff --git a/pkgs/development/python-modules/icalendar/default.nix b/pkgs/development/python-modules/icalendar/default.nix
index a7ed92051f65..c483932f3d4f 100644
--- a/pkgs/development/python-modules/icalendar/default.nix
+++ b/pkgs/development/python-modules/icalendar/default.nix
@@ -48,6 +48,8 @@ buildPythonPackage rec {
     # AssertionError: assert {'Atlantic/Jan_Mayen'} == {'Arctic/Longyearbyen'}
     "test_dateutil_timezone_is_matched_with_tzname"
     "test_docstring_of_python_file"
+    # AssertionError: assert $TZ not in set()
+    "test_add_missing_timezones_to_example"
   ];
 
   enabledTestPaths = [ "src/icalendar" ];