diff --git a/Ska/engarchive/fetch.py b/Ska/engarchive/fetch.py
index 4dae7433..0961c087 100644
--- a/Ska/engarchive/fetch.py
+++ b/Ska/engarchive/fetch.py
@@ -1424,7 +1424,10 @@ class MSIDset(collections.OrderedDict):
     """
     MSID = MSID
 
-    def __init__(self, msids, start=LAUNCH_DATE, stop=None, filter_bad=False, stat=None):
+    def __init__(self, msids=None, start=LAUNCH_DATE, stop=None, filter_bad=False, stat=None):
+        if msids is None:
+            msids = []
+
         super(MSIDset, self).__init__()
 
         intervals = _get_table_intervals_as_list(start, check_overlaps=True)
diff --git a/Ska/engarchive/tests/test_fetch.py b/Ska/engarchive/tests/test_fetch.py
index 5710720d..6d78f63b 100644
--- a/Ska/engarchive/tests/test_fetch.py
+++ b/Ska/engarchive/tests/test_fetch.py
@@ -1,6 +1,5 @@
 # Licensed under a 3-clause BSD style license - see LICENSE.rst
-from __future__ import print_function, division, absolute_import
-
+import pickle
 from copy import deepcopy
 
 import numpy as np
@@ -69,6 +68,35 @@ def test_filter_bad_times_list():
     assert np.all(dates == DATES_EXPECT1)
 
 
+@pytest.mark.parametrize('stat', [None, '5min'])
+def test_pickle_MSID(stat):
+    """Test pickling of MSID objects"""
+    msid = 'aoattqt1'
+    start, stop = '2022:001:00:00:00', '2022:001:00:15:00'
+    dat = fetch.MSID(msid, start, stop, stat=stat)
+    dat2 = pickle.loads(pickle.dumps(dat))
+    attrs = ('tstart', 'tstop', 'datestart', 'datestop', 'data_source', 'content')
+    for attr in attrs:
+        assert getattr(dat, attr) == getattr(dat2, attr)
+    for attr in ('times', 'vals'):
+        assert np.all(getattr(dat, attr) == getattr(dat2, attr))
+
+
+@pytest.mark.parametrize('stat', [None, '5min'])
+def test_pickle_MSIDset(stat):
+    """Test pickling of MSIDset objects"""
+    msid = 'aoattqt1'
+    start, stop = '2022:001:00:00:00', '2022:001:00:15:00'
+    dat = fetch.MSIDset([msid], start, stop, stat=stat)
+    dat2 = pickle.loads(pickle.dumps(dat))
+    attrs = ('tstart', 'tstop', 'datestart', 'datestop')
+    assert dat.keys() == dat2.keys()
+    for attr in attrs:
+        assert getattr(dat, attr) == getattr(dat2, attr)
+    for attr in ('times', 'vals') + attrs:
+        assert np.all(getattr(dat[msid], attr) == getattr(dat2[msid], attr))
+
+
 def test_msidset_filter_bad_times_list():
     dat = fetch.MSIDset(['aogyrct1'], '2008:291:12:00:00', '2008:298:12:00:00')
     dat.filter_bad_times(table=BAD_TIMES)