1 files changed, 6 insertions, 0 deletions
diff --git a/Lib/test/test_float.py b/Lib/test/test_float.py
index e1e1f04..bd2d6c3 100644
--- a/Lib/test/test_float.py
+++ b/Lib/test/test_float.py
@@ -6,6 +6,7 @@ from test import support
 import math
 from math import isinf, isnan, copysign, ldexp
 import operator
+import time
 import random, fractions
 
 INF = float("inf")
@@ -129,6 +130,11 @@ class GeneralFloatCases(unittest.TestCase):
         self.assertRaises(TypeError, float, Foo4(42))
         self.assertAlmostEqual(float(FooStr('8')), 9.)
 
+        class Foo5:
+            def __float__(self):
+                return ""
+        self.assertRaises(TypeError, time.sleep, Foo5())
+
     def test_is_integer(self):
         self.assertFalse((1.1).is_integer())
         self.assertTrue((1.).is_integer())