diff --git a/silverberg/marshal.py b/silverberg/marshal.py
index <HASH>..<HASH> 100644
--- a/silverberg/marshal.py
+++ b/silverberg/marshal.py
@@ -84,7 +84,7 @@ def marshal(term):
         # If the datetime is naive, then it is considered UTC time and stored. If it is
         # timezone-aware, then its corresponding UTC time is stored
         return str(int(calendar.timegm(term.utctimetuple()) * 1000 + term.microsecond / 1e3))
-    elif isinstance(term, sortedset):
+    elif isinstance(term, set) or isinstance(term, sortedset):
         # python str() produces: set([1, 2, 3]), while cassandra wants: {1, 2, 3}
         # so we have to marshal each element one by one.
         return '{%s}' % (', '.join(map(marshal, term)))
marshal both set and sortedset