diff --git a/Lib/test/test_float.py b/Lib/test/test_float.py
index 3f4998d..ab791a3 100644
--- a/Lib/test/test_float.py
+++ b/Lib/test/test_float.py
@@ -417,7 +417,13 @@
             '0x1p0\0 0x1p0',  # embedded null byte is not end of string
             ]
         for x in invalid_inputs:
-            self.assertRaises(ValueError, fromHex, x)
+            try:
+                result = fromHex(x)
+            except ValueError:
+                pass
+            else:
+                self.fail('Expected float.fromhex(%r) to raise ValueError; '
+                          'got %r instead' % (x, result))
 
 
     def test_from_hex(self):