diff --git a/datascience/util.py b/datascience/util.py
index b1289972..990e447e 100644
--- a/datascience/util.py
+++ b/datascience/util.py
@@ -254,6 +254,4 @@ def is_non_string_iterable(value):
         return False
     if hasattr(value, '__iter__'):
         return True
-    if isinstance(value, collections.abc.Sequence):
-        return True
     return False
\ No newline at end of file
diff --git a/tests/test_util.py b/tests/test_util.py
index f68ad617..b5d0f08e 100644
--- a/tests/test_util.py
+++ b/tests/test_util.py
@@ -72,7 +72,7 @@ def test_minimize():
 
 
 def test_minimize_smooth():
-    assert _round_eq(2, ds.minimize(lambda x: (x-2)**2, smooth=True))
+    assert _round_eq(2, ds.minimize(lambda x: (x-2)**2, smooth=True, log=print))
     assert _round_eq([2, 1], list(ds.minimize(lambda x, y: (x-2)**2 + (y-1)**2, smooth=True)))
     assert _round_eq(2, ds.minimize(lambda x: (x-2)**2, 1, smooth=True))
     assert _round_eq([2, 1], list(ds.minimize(lambda x, y: (x-2)**2 + (y-1)**2, [1, 1], smooth=True)))