diff --git a/Lib/test/test_builtin.py b/Lib/test/test_builtin.py
index 36b84d8..4057ba1 100644
--- a/Lib/test/test_builtin.py
+++ b/Lib/test/test_builtin.py
@@ -2068,6 +2068,15 @@
         class DerivedFromStr(str): pass
         self.assertEqual(format(0, DerivedFromStr('10')), '         0')
 
+    def test_bin(self):
+        self.assertEqual(bin(0), '0b0')
+        self.assertEqual(bin(1), '0b1')
+        self.assertEqual(bin(-1), '-0b1')
+        self.assertEqual(bin(2**65), '0b1' + '0' * 65)
+        self.assertEqual(bin(2**65-1), '0b' + '1' * 65)
+        self.assertEqual(bin(-(2**65)), '-0b1' + '0' * 65)
+        self.assertEqual(bin(-(2**65-1)), '-0b' + '1' * 65)
+
 class TestSorted(unittest.TestCase):
 
     def test_basic(self):