diff --git a/datascout/tests/test_timeconversion.py b/datascout/tests/test_timeconversion.py
index 79f6f2c62170bd5d6d8690b016db77aeade7a23a..5da5685f2919300b9e36f6458a26bc6587328d8c 100644
--- a/datascout/tests/test_timeconversion.py
+++ b/datascout/tests/test_timeconversion.py
@@ -25,6 +25,5 @@ def test_time():
     assert(ds.datetime_to_unixtime(myDateTime_unaware) == reference_stamp_us_precision)
 
     # can also work with strings
-    reference_time_str = ds.unixtime_to_string(reference_stamp, time_zone = 'cern')
-
-    assert(ds.string_to_unixtime(reference_time_str+' CET') == reference_stamp_us_precision)
+    reference_time_str = ds.unixtime_to_string(reference_stamp, time_zone = 'utc')
+    assert(reference_time_str == myDateTime_utc.strftime('%Y-%m-%d %H:%M:%S.%f'))