diff --git a/tests/test_opentime.py b/tests/test_opentime.py
index 1718f3d93..74143e29f 100755
--- a/tests/test_opentime.py
+++ b/tests/test_opentime.py
@@ -418,12 +418,16 @@ def test_faulty_formatted_timecode_24(self):
         with self.assertRaises(ValueError):
             otio.opentime.from_timecode('01:00:13;23', 24)
 
+    def test_faulty_time_string(self):
+        with self.assertRaises(ValueError):
+            otio.opentime.from_time_string("bogus", 24)
+
     def test_invalid_rate_to_timecode_functions(self):
         # Use a bogus rate, expecting `to_timecode` to complain
-        t = otio.opentime.RationalTime(100, 29.7)
+        t = otio.opentime.RationalTime(100, 999)
 
         with self.assertRaises(ValueError):
-            otio.opentime.to_timecode(t, 29.7)
+            otio.opentime.to_timecode(t, 777)
 
         with self.assertRaises(ValueError):
             otio.opentime.to_timecode(t)