diff --git a/Lib/test/test_builtin.py b/Lib/test/test_builtin.py
index f7b7c0c..a1e2a12 100644
--- a/Lib/test/test_builtin.py
+++ b/Lib/test/test_builtin.py
@@ -5,7 +5,7 @@
                               run_unittest, run_with_locale
 from operator import neg
 
-import sys, warnings, cStringIO, random, UserDict
+import sys, warnings, cStringIO, random, rational, UserDict
 warnings.filterwarnings("ignore", "hex../oct.. of negative int",
                         FutureWarning, __name__)
 warnings.filterwarnings("ignore", "integer argument expected",
@@ -688,6 +688,25 @@
         self.assertAlmostEqual(float(Foo3(21)), 42.)
         self.assertRaises(TypeError, float, Foo4(42))
 
+    def test_floatasratio(self):
+        R = rational.Rational
+        self.assertEqual(R(0, 1),
+                         R(*float(0.0).as_integer_ratio()))
+        self.assertEqual(R(5, 2),
+                         R(*float(2.5).as_integer_ratio()))
+        self.assertEqual(R(1, 2),
+                         R(*float(0.5).as_integer_ratio()))
+        self.assertEqual(R(4728779608739021, 2251799813685248),
+                         R(*float(2.1).as_integer_ratio()))
+        self.assertEqual(R(-4728779608739021, 2251799813685248),
+                         R(*float(-2.1).as_integer_ratio()))
+        self.assertEqual(R(-2100, 1),
+                         R(*float(-2100.0).as_integer_ratio()))
+
+        self.assertRaises(OverflowError, float('inf').as_integer_ratio)
+        self.assertRaises(OverflowError, float('-inf').as_integer_ratio)
+        self.assertRaises(ValueError, float('nan').as_integer_ratio)
+
     def test_getattr(self):
         import sys
         self.assert_(getattr(sys, 'stdout') is sys.stdout)