diff --git a/python/test/test_series.py b/python/test/test_series.py
index <HASH>..<HASH> 100644
--- a/python/test/test_series.py
+++ b/python/test/test_series.py
@@ -175,8 +175,6 @@ class TestSeriesMethods(PySparkTestCase):
         # detrending linearly increasing data should yield all 0s
         allclose(data.first()[1], array([0, 0, 0, 0, 0]))
 
-    # todo: currently failing with Exception("No indices found matching criterion")??
-    @unittest.skip
     def test_series_stats(self):
         rdd = self.sc.parallelize([(0, array([1, 2, 3, 4, 5]))])
         data = Series(rdd)
diff --git a/python/thunder/rdds/series.py b/python/thunder/rdds/series.py
index <HASH>..<HASH> 100644
--- a/python/thunder/rdds/series.py
+++ b/python/thunder/rdds/series.py
@@ -68,7 +68,8 @@ class Series(Data):
         index = self.index
 
         if not isinstance(crit, types.FunctionType):
-            critlist = set(crit)
+            # set("foo") -> {"f", "o"}; wrap in list to prevent:
+            critlist = set([crit]) if isinstance(crit, basestring) else set(crit)
             crit = lambda x: x in critlist
 
         newindex = [i for i in index if crit(i)]
fix set creation causing test failure, reenable test